Histopathology of lupus-like nephritis in Dnase1-deficient mice in comparison to NZB/W F1 mice

Deoxyribonuclease 1 (Dnase1)-deficient mice develop symptoms of Systemic lupus erythematosus (SLE). Here we analysed the renal histopathology of these animals in comparison to F1 hybrids of New Zealand black and white mice (NZB/W F1), an established model of SLE. Animals were divided into three groups according to the presence of anti-nuclear antibodies (ANA) and renal lesions. Groups 1a-1c were healthy, whereas group 2 and 3 were classified as lupus-prone and affected. Subendothelial and/or mesangial immune complex deposits, mesangial and endocapillary proliferation, haematoxylin bodies and platelet aggregation were detected in both mouse strains but were more severe in the NZB/W F1 mice. The lupus nephritis was classified as a proliferating (WHO type III or IV), which appeared to be preceded by a mesangial form (WHO type II). Subclassification of the ANA revealed a high prevalence of anti-nucleosome antibodies in Dnase1-deficient mice, whereas NZB/W F1 mice developed autoantibodies against a broad range of chromatin constituents. Mapping of the murine Dnase1 gene locus to chromosome 16A1-3 did not coincide with one of the reported susceptibility loci in the NZB/W F1 model, although a reduced Dnasel serum and urine activity has been described previously in these mice.

IMPORTED CUTANEOUS LEIHSMANIASIS IN A NEPALI CITIZEN

ABSTRACT

Clinicopathological and mycological spectrum of allergic fungal sinusitis in South India

In the present study, we describe characteristic clinicopathological and radiological features as well as fungal culture results in a series of 24 patients with allergic fungal sinusitis (AFS). Nasal obstruction and discharge with nasal polyposis was the commonest (95.8%) clinical presentation. Allergic mucin was uniformly present in all patients. Aspergillus species were the commonest fungal isolates (95.8%). One case of mixed Aspergillus and Curvularia sinusitis as well as one case of Drechslera sinusitis were also identified. Typical computerized tomography scan features of hyperdense areas interspersed with soft tissue densities in the affected sinuses were seen in all patients. Application of appropriate diagnostic criteria is essential to establish the diagnosis of AFS and distinguish it from invasive fungal sinus infections.

Problems of classification of Henoch Schonlein purpura: an Indian perspective

A 2-year prospective study was carried out in which 71 patients with primary cutaneous vasculitis were classified using the American College of Rheumatology (ACR) classification and the Chapel Hill Consensus Conference (CHCC) recommendations for Henoch Schonlein purpura (HSP). The sensitivity of the ACR criteria was 64.8% and that of the CHCC definition 31%. When the ACR criteria were combined with results of direct immunofluorescence (DIF) the sensitivity was 78.9%. The concordance between the two systems was low as only 12 patients fulfilled criteria for both classifications. Although the ACR criteria were found to be more useful in the classification of HSP our data suggest that they need to be modified to include adults with disease. The age at onset of disease was higher than that in the west. Seventy per cent of patients identified by either classification were > 20 years of age. The prevalence of gut involvement, microhaematuria and proteinuria was < 25% in both groups. The sensitivity of histopathology on the other hand was 80.4% and was not influenced by the duration of the lesion. The DIF test was a useful adjunct to histopathology if it was done within 48 h as the yield of a positive test was significantly higher in this group as compared to the patients who had the test done later.

Spray-dried microparticulate systems containing acetaminophen

The present work investigates the preparation and the release of acetaminophen from spray-dried microparticles. Two cellulose derivatives were tested as sustaining agents: microcrystalline cellulose (MCC) and sodium carboxymethylcellulose (NaCMC). In-vitro dissolution studies were carried out in dissolution media of different pH. With MCC, the adsorption of acetaminophen on the surface or in the pores of the polymer does not allow a significant sustained release of the drug, which completely dissolves in 1 h. Conversely, the use of NaCMC retards the release of acetaminophen over a period of 6-8 h. The drug release depends on the plasticizer used and on the pH of the dissolution medium, and the mechanism consists essentially in the diffusion of the drug through the swollen polymeric matrix. The pH dependence observed can be correlated with a lower hydrophylicity of the polymer in acidic medium, which retards gel formation.

Determination of L-pipecolic acid in plasma using chiral liquid chromatography-electrospray tandem mass spectrometry

BACKGROUND

L-pipecolic acid (L-PA), an important biochemical marker for the diagnosis of peroxisomal disorders, is usually determined as the racemate. We developed a chiral liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the analysis of L-PA in plasma.

METHODS

We used a narrow bore chiral macrocyclic glycopeptide teicoplanin column for the enantioseparation of D-pipecolic acid (D-PA) and L-PA and interfaced the column directly to the electrospray source of a tandem mass spectrometer. We used phenylalanine-d5 as internal standard added to 50 microL of plasma followed by deproteinization, evaporation, and injection. The analysis was performed in the selected-reaction monitoring mode using two transitions: m/z 130-->m/z 84 for PA, and m/z 171-->m/z 125 for phenylalanine-d5. L-PA eluted at 7 min, and D-PA eluted at 11.7 min, whereas phenylalanine-d5 eluted at 6 min. The turnaround time for the assay was 20 min.

RESULTS

Linear calibration curves were obtained in the range of 0.5-80 micromol/L. At a plasma concentration of 1.0 micromol/L, the signal-to-noise ratio was 50:1. The intra- and interassay variations were 3.1-7.9% and 5.7-13%, respectively, at concentrations of 1-50 micromol/L. Mean recoveries of L-PA added to plasma were 95% (5 micromol/L) and 102% (50 micromol/L). The method clearly distinguished between healthy individuals and peroxisomal disease patients.

CONCLUSIONS

The novel LC-MS/MS method is simple, rapid, and stereoselective, and uses only 50 microL of plasma, no derivatizing reagents, and a commercially available internal standard. Sample preparation is not complex and is faster than for all other methods.

Effects of indomethacin on energy metabolism in rat and human jejunal tissue in vitro

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to cause enteropathy, but the mechanism by which this toxicity occurs is less well established. This paper sets out to test the hypothesis that these drugs affect oxidative phosphorylation in jejunal tissue, thereby interfering with energy metabolism and rendering the tissue vulnerable to damage. Jejunal tissue obtained from rats and humans was used for in vitro determinations of oxygen uptake, lactate production and energy charge levels in the presence of indomethacin, a commonly used NSAID. In the rat jejunal tissue, drug concentrations of 0.5 mM and 2.5 mM produced significant decreases in oxygen uptake (P<0.01) and energy charge levels in the tissue (P<0.05). There was a corresponding increase in lactate production by the tissue at these indomethacin concentrations (P<0.05). Rat jejunum examined by electron microscopy after incubation with various concentrations of indomethacin showed ultrastructural effects of the drug on mitochondrial morphology. In human tissue, an inhibitory effect of indomethacin on oxygen uptake was seen, but the effects on lactate production and energy charge were less conclusive. These findings suggest that indomethacin affects mitochondria and thereby impairs energy metabolism in jejunal tissue.

A study of the effects of indometacin on liver mitochondria from rats, mice and humans

BACKGROUND

A part of the mechanism of the gastrointestinal toxicity exhibited by non-steroidal anti-inflammatory drugs is believed to involve the uncoupling of mitochondrial oxidative phosphorylation. Most previous uncoupling studies have used rat liver mitochondria. There is little information on the effects of the drugs on mitochondria from other species.

AIM

To study the effect of indometacin on isolated liver mitochondria from rats, mice and humans.

METHODS

We studied the effects of indometacin on respiration and adenosine triphosphate synthesis by isolated liver mitochondria from rats, mice and humans. Its effects were compared with those of dinitrophenol, a classical uncoupler.

RESULTS

Indometacin uncoupled oxidative phosphorylation at low concentrations (P < 0.05) and inhibited respiration at high concentrations (P < 0.01) in all three species. Adenosine triphosphate synthesis was, however, more sensitive to dinitrophenol or indometacin at lower concentrations in mouse and human compared to rat liver mitochondria (P < 0.05).

CONCLUSIONS

The current study shows that indometacin acts as an inhibitory uncoupler in human mitochondria. It also demonstrates that the responses of rat, mouse and human mitochondria to indometacin are broadly similar.

Changes in blood volume and hematocrit during acute preoperative volume loading with 5% albumin or 6% hetastarch solutions in patients before radical hysterectomy

BACKGROUND

The impact of acute preoperative volume loading with colloids on blood volume has not been investigated sufficiently.

METHODS

Before surgery, in 20 patients undergoing major gynecologic procedures, volume loading was performed during anesthesia by infusing approximately 20 ml/kg of colloid at a rate of 90 ml/min (group I: 5% albumin solution; group II: 6% hetastarch solution; n = 10 each). Plasma volume (indocyanine green dilution technique), erythrocyte volume (labeling erythrocytes with fluorescein), hematocrit, total protein, and hetastarch plasma concentrations (group II) were measured before and 30 min after the end of infusion.

RESULTS

More than 1,350 ml of colloid (approximately 50% of the baseline plasma volume) were infused within 15 min. Thirty minutes after the infusion had been completed, blood volume was only 524 +/- 328 ml (group I) and 603 +/- 314 ml (group II) higher than before volume loading. The large vessel hematocrit (measured by centrifugation) dropped more than the whole body hematocrit, which was derived from double-label measurements of blood volume.

CONCLUSIONS

The double-label measurements of blood volume performed showed that 30 min after the infusion of approximately 20 ml/kg of 5% albumin or 6% hetastarch solution (within 15 min), only mean 38 +/- 21% and 43 +/- 26%, respectively, of the volume applied remained in the intravascular space. Different, i.e., earlier or later, measuring points, different infusion volumes, infusion rates, plasma substitutes, or possibly different tracers for plasma volume measurement might lead to different results concerning the kinetics of fluid or colloid extravasation.

[Acute "normovolemic" hemodilution with 3.5% polygel (Haemaccel) for patients in the Wertheim-Meigs-operation. Blood loss of 87% blood volume without perioperative blood transfusion]

QUESTION

Is polygeline (Haemaccel) a suitable colloid to perform preoperative acute normovolemic hemodilution (ANH) and to replace a large intraoperative blood loss?

METHODS

In a sixty-eight-year-old patient undergoing radical hysterectomy preoperative ANH was performed to a hematocrit of 23% using 3.5% polygeline (Haemaccel). Intraoperative retransfusion of ANH blood was started at a hematocrit of 13%. Plasma volume (indocyanine green-dilution technique) and hematocrit were measured before and after ANH, 3 times intraoperatively (once before retransfusion) and postoperatively. Red cell volume (by labelling erythrocytes with fluorescein) was determined before and after ANH, before retransfusion, and postoperatively.

RESULTS

After removal of 1,940 ml of blood and replacement with 15% more of colloid, blood volume decreased by 760 ml. After a mean blood loss of 4,600 ml, 290 ml and 260 ml of red cells were saved due to ANH and use of a cell saver, respectively.

CONCLUSIONS

The exact double label measurements of blood volume demonstrated that polygeline, which has a volume effect of only 50%, cannot be considered to be a suitable colloidal substitute during ANH.

Increasing diagnostic yield in allergic fungal sinusitis

Diagnosis of allergic fungal sinusitis (AFS) in patients who present with rhinosinusitis and polyposis is based upon certain clinical, histopathological and mycological histopathological criteria are the demonstration of fungal hyphae in allergic mucin and absence of tissue invasion in the excised polyps. Previous reports have indicated difficulty in demonstrating fungal hyphae on histological examination in up to 75 per cent of cases. Analysis of a series of 25 patients with AFS, suggested methods to ensure demonstration of fungal hyphae and thus increase diagnostic yield in cases with suspected AFS. criteria. Specific diagnostic

Identification of a third rat odorant-binding protein (OBP3)

From a rat olfactory epithelium cDNA library clones encoding a lipocalin were isolated with sequence identity to the previously described salivary-specific alpha-2u globulin and the N-terminal region of mouse odorant-binding proteins OBP-III and OBP-IV. In situ hybridization showed strong expression in nasal glands displaying a pattern equivalent to rat OBP1. Heterologously expressed protein was evaluated for its binding properties using spectroscopic approaches. The recombinant protein interacted with two fluorescent probes, 1-aminoanthracene (1-AMA) and 1,1'-bis(4-anilino-5-naphthalene)-sulfonic acid. 1-AMA binding was competed by several odorants with high affinity. The thermodynamic parameters of the protein-odorant interaction were determined using isothermal titration calorimetry. Due to its nasal expression and odorant-binding characteristics this protein was designated OBP3.

Neurocutaneous melanosis: a case of primary intracranial melanoma with metastasis

Neurocutaneous melanosis is a rare disorder characterized by the presence of large or multiple congenital melanocytic naevi and benign or malignant pigment cell tumours of the leptomeninges. Distant metastasis is unusual in primary leptomeningeal/intracranial melanomas. We present the case history of an adult male who had multiple primary intracranial melanomas associated with neurocutaneous melanosis (naevus of Ota) in the ophthalmic division of the left trigeminal nerve. Excision of the intracranial tumours was carried out in two stages, but the patient died 2 days after the second operation. Autopsy showed multiple metastatic deposits in the liver. Symptoms and signs of raised intracranial pressure, the presence of Ota's naevus, and a dural-based mass or masses should alert the treating physician to suspect a primary leptomeningeal/intracranial melanoma.

Human retinal pigment epithelium secretes a phospholipase A2 and contains two novel intracellular phospholipases A2

The sensitivity of different phospholipase A2 (PLA2)-active fractions eluted from cation-exchange chromatography to para-bromophenacylbromide (pBPB), Ca2+-EGTA, DTT, heat, and H2SO4 indicates that human cultured retinal pigment epithelial (hRPE) cells probably contain two different intracellular PLA2 enzymes. Control experiments using "back-and-forth" thin-layer chromatography confirmed that, in our assay conditions, the generation of free fatty acids originated solely from PLA2 activity. Together with immunoblot experiments where no cross-reactivity was observed between the hRPE cytosolic PLA2 enzymes and several antisera directed against secretory PLA2s (sPLA2s) and cytosolic PLA2 (cPLA2), these findings suggest that intracellular hRPE PLA2s are different from well-known sPLA2s, cPLA2, and Ca2+-independent PLA2s. We also report an additional hRPE-PLA2 enzyme that is secreted and that exhibits sensitivity to pBPB, Ca2+-EGTA, DTT, heat, and H2SO4, which is characteristic of sPLA2 enzymes. This approximately 22-kDa PLA2 cross-reacted weakly with an antiserum directed against porcine pancreatic group I sPLA2 but strongly with an antiserum directed against N-terminal residues 1-14 of human synovial group II sPLA2, suggesting that this extracellular enzyme is a member of the sPLA2 class of enzymes. We thus conclude that there are three distinct PLA2 enzymes in cultured hRPE cells, including two novel intracellular PLA2s and a 22-kDa secreted sPLA2 enzyme.

A pilot study of HTLV-I infection in high-risk individuals & their family members from India

BACKGROUND & OBJECTIVES

Human T lymphotropic virus-I (HTLV-I) has been associated with adult T cell lymphoma/leukemia (ATLL). There are Indian studies on HTLV-I infection among people with sexually transmitted infection, but no large study has been conducted on individuals with haematological malignancies. In this group of individuals, serology is known to under-diagnose HTLV-I infection. This study was carried out to identify serologically and where possible with molecular techniques, HTLV-I infection in individuals with haematological malignancies. To understand the modes of transmission, family members of individuals with proven HTLV-I infection were also studied. Individuals with sexually transmitted infection (STI), blood donors and pregnant women were also studied.

METHODS

Particle agglutination test was used to detect antibody to HTLV-I. HTLV genome was amplified by polymerase chain reaction (PCR) and detected with probes by digoxiginin (Dig) ELISA.

RESULTS

There was no serological evidence of HTLV-I infection among the healthy blood donors and pregnant women studied. High prevalence of anti-HTLV-I antibody was identified in the patients with haematological malignancies (8 of 86 patients, 9.3%) and a lower prevalence in individuals with STI (8 of 670 individuals, 1.2%). In the STI group, all 8 individuals seroreactive to HTLV-I were coinfected with human immunodeficiency virus (HIV). In the group with haematological malignancies, three of 22 (13.6%) patients with leukemia, 3 of 11 (27.3%) with cutaneous T-cell lymphoma (CTCL) and 2 of 53 (3.8%) with lymphoma were reactive for anti-HTLV-I antibody. In this group, PCR identified all the seroreactive individuals tested. There were also seronegative infected individuals who were only identified by PCR. There was also a large number of seronegative family members who were only positive by PCR.

INTERPRETATION & CONCLUSION

The study revealed a strong disease association of HTLV-I with haematological malignancies and evidence for both horizontal and vertical transmission of the infection in the Indian population. HTLV-I infection appears to be common among family members of individuals with HTLV-I associated haematological malignancies.

Rapid therapeutic response onset of a new pharmaceutical form of chloroquine phosphate 300 mg: effervescent tablets

OBJECTIVE

To compare the efficiency, safety and taste of two pharmaceutical forms of chloroquine phosphate 300 mg: effervescent tablets against uncoated tablets.

METHOD

An open randomized study with 60 adults who suffered from acute uncomplicated Plasmodium falciparum malaria in three health centres in Nkongsamba health district, Cameroon.

RESULTS

Mean times to fever clearance, symptoms clearance and asexual parasites clearance were longer in the uncoated tablets group: 36 h (range 24-48 h, SD = 16.8) vs. 60 h (range 24-96 h, SD = 31.2, P = 0.001) for fever clearance, 36 h (24-48 h, SD = 16.8) vs. 48 h (24-72, SD = 24, P = 0.001) for symptoms clearance and 48 h (24-72, SD = 1) vs. 72 h (48-96, SD = 24, P = 0.001) for parasitaemia clearance. Uncoated tablets took significantly longer to achieve 50% reduction of the initial asexual parasite density: (mean/SD) 19.2 h/7 vs. 52.8 h/16.8, P < 0.00001. The adverse effects in the two groups were similar, P > 0.05. The cure rate at day 7 in the two groups was similar, P > 0.05. There was no chloroquine resistance in the effervescent tablets group but one RI and one RII resistance in the uncoated tablets group. The taste of the two pharmaceutical forms was significantly different, P < 0.00001. Effervescent tablets tasted sweet (score = 7.93), whereas uncoated tablets were bitter (score = 2.07).

CONCLUSION

Effervescent tablets of chloroquine phosphate 300 mg work faster than uncoated tablets and because of their safe use and sweet taste achieve good therapeutic compliance.

A clinico-mycological study of dermatophytoses in Nepal

A clinico-mycological study of 100 cases of dermatophytosis was done in the B.P. Koirala Institute of Health Sciences in the eastern region of Nepal. The incidence of dermatophytoses in this study was 4.54% with a M: F ratio of 2.5: 1. The commonest age group was 11-20 years old. A single clinical type was found in 68%; 32% had two or more clinical types. The study revealed tinea corporis (43%) as the most common clinical type followed by tinea cruris (33%) and tinea pedis (20%). Positive culture was obtained in 94% of cases. A total of eight different species of dermatophytes were isolated with T. rubrum (45.74%) as the most common species followed by T. mentagrophytes (26.6%), T. tonsurans (11.7%), M. audouinii (8.36%), E. floccosum (4.26%), T. schoenlenii (2.13%), T. violaceum (2.13%) and T. verrucosum (1.06%).

Technical knowledge and the mental universe of Manchester's early cotton manufacturers

Through the reinterpretation of evidence long available but still underutilized, the authors explore the role of mechanical and technical knowledge in the making of the industrial revolution in cotton. Traditionally, science — understood in eighteenth-century Britain to be largely, although not exclusively, the science of mechanics — has been seen to have little to do with spinning machines and power weaving. But the steam engine required a degree of technical knowledge which the leaders in Manchester cotton manufacturing possessed. Furthermore, this study of Manchester in the period from 1790 to 1820 focuses on the urban setting as a locus of innovation and the chapel life of Unitarians as providing a site for the inculcation of religious values compatible with an ethic for both entrepreneurs and workers. The article contributes to the growing (and often neo-Weberian) cultural history of the first Industrial Revolution. M’Connell and Kennedy led the Manchester cotton industry for over two decades and they stamped their values and knowledge base into the community through their avid participation in scientific societies and chapel life. Their manuscripts at the John Rylands Library, Deansgale, Manchester form the core of this article.

Process to manufacture effervescent tablets: air forced oven melt granulation

In the present study we apply melt granulation in an air forced oven, called "are forced oven melt granulation" to the single-stage manufacture of effervescent granules consisting of anhydrous citric acid (43.2%) and sodium bicarbonate (56.8%) in order to make tablets. This study established that process parameters such as concentration of PEG 6000, residence time in the air forced oven, fineness of PEG 6000, fineness of the initial effervescent mix and efficiency of two lubricants markedly influenced several granule and tablet characteristics. The granules ready to be compressed into tablets were stable for 7 days at 60% RH/18 degrees C. It is a dry, simple, rapid, effective, economical, reproducible process particularly well suited to the manufacture of effervescent granules which are easily compressed into effervescent tablets. Of all the formulations tested, only formulations B2 and E2 melt granulated for 30 minutes gave tablets which had optimum compression characteristics without processing problems during compression.

Policy understanding of science, public trust and the BSE-CJD crisis

The article investigates how institutional factors can produce risk using the Bovine Spongiform Encephalopathy (BSE)-Creutzfeldt-Jakob Disease (CJD) crisis in Britain as a case example. The paper focuses on the way policymakers understand science, and the role of precaution in issues of high uncertainty. It is argued that the failure to fully appreciate the complexity of the BSE-CJD situation resided in institutional arrangements that predisposed decision makers to adopt a counter productive approach in handling situations of high scientific uncertainty on the policy level. The article will demonstrate how these factors played out in the BSE-CJD crisis.

A process to produce effervescent tablets: fluidized bed dryer melt granulation

The purpose of the present study was to apply melt granulation in a fluidized bed dryer (fluidized bed dryer melt granulation) to manufacture one-step effervescent granules composed of anhydrous citric acid and sodium bicarbonate to make tablets. This study permitted us to establish that such process parameters as concentrations of polyethylene glycol (PEG) 6000, residence times in the fluidized bed dryer, fineness of PEG6000, fineness of initial mixture effervescent systems, and efficiency of two lubricants markedly affect some granule and tablet characteristics. It is a dry process that is simple, rapid, effective, economical, reproducible, and particularly adapted to produce effervescent granules that are easily compressed into effervescent tablets.

Early development of the müllerian duct in avian embryos with reference to the human. An ultrastructural and immunohistochemical study

In vertebrates, the female reproductive system arises from the Müllerian (paramesonephric) duct which develops in both sexes under the influence of the Wolffian (mesonephric) duct. For a better understanding of the interactions between the Müllerian duct and its adjacent tissues, we present a systematic scanning and transmission electron microscopic investigation of early stages of avian Müllerian duct development. This starts within the cranial part of the Müllerian ridge from a placode-like thickening and deepening of the coelomic epithelium containing nephrostomes as remnants of the last pronephric and first mesonephric tubules. Groups of cells detach from this placode and rapidly expand caudally as a solid cord. This becomes canalized, but the tip region remains mesenchymal and is found enclosed within the basal lamina of the Wolffian duct. Immunostaining reveals that the Müllerian duct migrates within a matrix rich in laminin and entactin. When the canalized duct has opened into the coelomic cavity, one or more secondary ducts are found immediately caudal of the main funnel, for a short period only, possibly to supply material to the expanding duct. BrdU-anti-BrdU reaction reveals a high proliferation of the duct epithelium. The thickened epithelium of the Müllerian ridge dissolves to form the mesenchymal layers of the duct. Immunostaining with vimentin argues against a cellular contribution of Wolffian duct cells to the Müllerian duct. Comparing the data from avian embryos with those of human indicates that the modalities of early Müllerian duct development are similar in both species.

Development of spray-dried acetaminophen microparticles using experimental designs

Experimental factorial designs were built to investigate the effects of five parameters on production yields and moisture contents of spray-dried products. These factors concerned both the solution feed (drug concentration, colloidal silica concentration and polymer/drug ratio) and the spray dryer (inlet temperature and feed rate). Three formulations containing cellulose derivatives and acetaminophen were tested. The aim of the study was to optimize the operating conditions to maximize production yields while minimizing moisture contents. First screening experiments consisting of fractional factorial designs revealed the most significant factors to be inlet temperature, feed rate and their interaction for both formulations containing sodium carboxymethylcellulose and feed rate and colloidal silica concentration for the formulation containing microcrystalline cellulose. Then, the optimal operating conditions were estimated by response surface methodology. Central rotational composite designs showed quadratic models were adequate. New assays were carried out using these last conditions to evaluate both the repeatability and reproducibility of the spray-drying technique. Yields above 80% and moisture content of approximately 1% were reached. The characterization of microparticles revealed the poor flowability of the spray-dried products due to significant cohesiveness and very small size (less than 55 microm).

Uncoupling of intestinal mitochondrial oxidative phosphorylation and inhibition of cyclooxygenase are required for the development of NSAID-enteropathy in the rat

BACKGROUND

The pathogenesis of NSAID-induced gastrointestinal damage is believed to involve a nonprostaglandin dependent effect as well as prostaglandin dependent effects. One suggestion is that the nonprostaglandin mechanism involves uncoupling of mitochondrial oxidative phosphorylation.

AIMS

To assess the role of uncoupling of mitochondrial oxidative phosphorylation in the pathogenesis of small intestinal damage in the rat.

METHODS

We compared key pathophysiologic events in the small bowel following (i) dinitrophenol, an uncoupling agent (ii) parenteral aspirin, to inhibit cyclooxygenase without causing a 'topical' effect and (iii) the two together, using (iv) indomethacin as a positive control.

RESULTS

Dinitrophenol altered intestinal mitochondrial morphology, increased intestinal permeability and caused inflammation without affecting gastric permeability or intestinal prostanoid levels. Parenteral aspirin decreased mucosal prostanoids without affecting intestinal mitochondria in vivo, gastric or intestinal permeability. Aspirin caused no inflammation or ulcers. When dinitrophenol and aspirin were given together the changes in intestinal mitochondrial morphology, permeability, inflammation and prostanoid levels and the macro- and microscopic appearances of intestinal ulcers were similar to indomethacin.

CONCLUSIONS

These studies allow dissociation of the contribution and consequences of uncoupling of mitochondrial oxidative phosphorylation and cyclooxygenase inhibition in the pathophysiology of NSAID enteropathy. While uncoupling of enterocyte mitochondrial oxidative phosphorylation leads to increased intestinal permeability and low grade inflammation, concurrent decreases in mucosal prostanoids appear to be important in the development of ulcers.

4-Hydroxyisoleucine: effects of synthetic and natural analogues on insulin secretion

4-Hydroxyisoleucine, a peculiar amino acid extracted from fenugreek seeds and never found in mammalian tissues, exhibits interesting insulinotropic activity. To investigate the structural requirements for this stimulating effect, the insulinotropic activity of the major isomer (2S,3R,4S) of 4-hydroxyisoleucine, in the presence of 8. 3 mM glucose, was compared to that of (1) its minor isomer (2R,3R, 4S) (2) its lactone form, (3) classical structurally related amino acids, and (4) synthetic monomethylated analogues. In the isolated, ex vivo, perfused rat pancreas, only the major isomer of 4-hydroxyisoleucine (200 microM) potentiated insulin release. On incubated isolated rat islets, the threshold concentration for a significant increase (P<0.05) in insulin release was 200 microM for (2S,3R,4S) 4-hydroxyisoleucine, 500 microM for (2S,4R) and (2S,4S) gamma-hydroxynorvalines as well as (2S,3S) and (2S,3R) gamma-hydroxyvalines, and 1 mM or more for other congeners. In conclusion, the insulinotropic properties of 4-hydroxyisoleucine, in the micromolar range, are seen only in the presence of the linear major isoform; they also require carbon alpha in S-configuration, full methylation and carbon gamma-hydroxylation.

[The carbon dioximeter: a device for quantifying the carbon dioxide released from effervescent pharmaceuticals]

Since effervescent pharmaceuticals are more sensitive to ambient humidity during the manufacturing process and storage, the strict control of their carbon dioxide content becomes a prerequisite to guarantee their physicochemical stability. Indirect gravimetry is a simple and precise method that consists in taking the weight before and after the effervescent reaction allowing to determine the released amount of carbon dioxide. Some authors have used it with devices that lead to longer analysis times and poor accuracy of measurements (due to the excess of released carbon dioxide). The device that we have built (proposed name "CARBONDIOXIMETER") is very easy to set up, and yields quick, accurate, precise and reproducible results. An assay takes three minutes in an acidic medium and five minutes in carbon dioxide free water). Moreover, through the interconnection of scales, registration and treatment of the results can be performed by a printer or a computer. Thus, the "Carbondioximeter" is contributing to the control of physicochemical stability of effervescent pharmaceuticals during the manufacturing process and storage.

Effects of cellulose derivatives and additives in the spray-drying preparation of acetaminophen delivery systems

Microcrystalline cellulose (MCC), sodium carboxymethylcellulose (NaCMC), hydroxypropylmethylcellulose (HPMC), hydroxyethylcellulose (HEC), hydroxypropylcellulose (HPC), and ethylcellulose (EC) were used for the production of time-controlled acetaminophen delivery systems using a spray-drying technique. The influence of factors such as polymer concentration, inlet temperature, and drug/polymer ratio were investigated. The product yields were a function of the type and concentration of the polymer, with the highest values being reached from feeds containing 1% MCC and EC. Parameters of 1% polymer concentration and an inlet temperature of 140 degrees C gave rise to optimal processing conditions. Using these parameters, the influence of some adjuncts, such as polyethylene glycol 6000 (PEG 6000), dibutyl sebacate (DBS), polyvinylpyrrolidone (PVP), and carboxylic acids such as citric acid (CA), phthalic acid (PA), succinic acid (SA), tartaric acid (TA), and oxalic acid (OA), on the spray-drying process was evaluated. Of the additives tested, PVP (with MCC), DBS (with EC), and PEG 6000 (with NaCMC) induced yield decreases from 70% to 49%, 66% to 39%, and 37% to 17%, respectively. As for carboxylic acids (with NaCMC), similar or better performances of 43%, 45%, 47%, and 49% were obtained with SA, OA, PA, and TA, respectively. Dissolution studies in pH 1 dilute HCl and pH 6.8 phosphate buffer dissolution media showed that formulations consisting of 1% polymer with a drug/polymer ratio of 1/1 exhibited the slowest drug release, with the spheroids coated with NaCMC and HEC showing the longest T50% values (with 45 and 53 min at pH 1 and 49 and 55 min at pH 6.8, respectively). Slightly better sustained drug release in pH 6.8 dissolution medium was reached, showing the following trend: HEC > NaCMC > MCC > EC > HPMC. Concerning the additives, the trends in dissolution T50% of drug revealed TA > SA > CA > OA > PVP > PA > DBS in acidic pH 1 dissolution medium and PVP > OA > TA > SA > PA > CA > DBS in phosphate buffer at pH 6.8.

Protein folding as a diffusional process

A protein chain must move relative to the solvent molecules and explore many conformations when it folds from the extended unfolded state to the compact native state. Experimental and theoretical approaches suggest that diffusional processes in fact contribute to the kinetics of protein folding. We describe here how variations of the solvent viscosity can be employed to uncover the diffusional contributions to a folding reaction and assess the use of transition state theory and Kramers' rate theory for the analysis of protein folding reactions.

Comparative study of shape, course, and disintegration of the rostral notochord in some vertebrates, especially humans

The rostral part of the notochord reveals many peculiarities compared with the trunk mesoderm. Furthermore, its role in head formation and inductive processes in the head is not as well understood as the interaction of the trunk notochord with the spinal cord and somites. To interpret experimental and molecular biological examinations in the developing head region, exact knowledge about morphological features of the rostral notochord is fundamental. Here we show that the rostral notochord reveals variations that depend on species and individual. We describe morphological characteristics of the rostral (head) notochord in human embryos (Carnegie stages X-XIV), which are shown in semithin sections and three-dimensional graphic reconstructions. Special attention is paid to the relationship of the notochord with the prechordal mesoderm and the adenohypophysis. We propose that in the human the rostral notochordal tip terminates at Rathke's pouch, whereas in the chick prechordal mesoderm is found in between the notochordal tip and the anlage of the adenohypophysis. The behaviour of the notochord at the end of the embryonic period proper and early fetal time is shown in sagittal histological sections of 16 to 49 mm CRL human embryos. Position and disintegration of the rostral notochord is also described in embryos of cat (8-25 mm), mouse (stage 21-24 according to Theiler) and chicken (stage 22-26 HH). A synopsis reveals the different course of the notochord within, at the inner or outer side of the basioccipital cartilage. The course of rostral notochord is determined by its attachment points at the hypophysis, the pharynx or the footplate of the brain. In all species, it has an undulating course. Its rostral tip is highly coiled, and fragments or splinters are found within the anlage of the dorsum sellae. Thus, we have reasons to believe that the adenohypophysis is a hindrance for the rostral elongation of the notochord. Variable adhesions between notochord and pharyngeal epithelium are considered to be responsible for invaginations of the pharyngeal wall forming bursae pharyngeae. In contrast to other authors, we observed in the mouse that rostrally the notochord bends ventral and penetrates the chondrocranium at the level of the later synchondrosis basisphenoidale to build a bursa pharyngea. Finally, partial duplications of two human notochords are described.

Diffusional barrier crossing in a two-state protein folding reaction

There has been some debate as to whether protein folding involves diffusive chain motions and thus depends on solvent viscosity. The interpretation of folding kinetics in viscous solvents has remained difficult and controversial, in that viscogenic agents affect folding rates not only by increasing solvent viscosity but also by increasing protein stability. By carefully choosing experimental conditions, we can now eliminate the effect on stability and show that the folding dynamics of the cold shock protein CspB are viscosity dependent. Thus Kramers' theory of reaction rates rather than transition state theory should be used to describe this folding reaction.

Pyoderma gangrenosum associated with ulceratlve colitis-first case report from Nepal

A case of pyoderma gangrenosum with ulcerative colitis from Nepal is reported. The patient responded well to a combination of oral steroids, clofazimine. dapsone and salazopyrine within a period of 3 months.

Erythrokeratoderma en cocardes

The erythrokeratodermas are a distinct but clinically variable group of rare geno-dermatoses, characterized by circumscribed erythematous and hyperkeratotic lesions. All attempts to establish a valid classification have been based on purely clinical and morphologic criteria. Erythrokeratoderma en cocardes, also known as genodermatose en cocardes or Degos' syndrome, was first described by Degos in 1947. The condition is characterized by large round plaques with concentric erythema and scaling having a target configuration, which remit and recur, in addition to scaly plaques as seen in erythrokeratoderma variabilis. A case of this rare genodermatosis is described.

Microsecond folding of the cold shock protein measured by a pressure-jump technique

A pressure-jump apparatus was employed in investigating the kinetics of protein unfolding and refolding. In the reaction cell, the pressure can be increased or decreased by 100-160 bar within 50-100 microseconds and then held constant. Thus, unfolding and refolding reactions in the time range from 70 microseconds to 70 s can be followed with this technique. Measurements are possible in the transition regions of thermally or denaturant-induced folding in a wide range of temperatures and solvent conditions. We used this pressure-jump method to determine the temperature dependence of the rate constants of unfolding and refolding of the cold shock protein of Bacillus subtilis and of three variants thereof with Phe --> Ala substitutions in the central beta-sheet region. For all variants, the change in heat capacity occurred in refolding between the unfolded and activated states, suggesting that the overall native-like character of the activated state of folding was not changed by the deletion of individual Phe side chains. The Phe27Ala mutation affected the rate of unfolding only; the Phe15Ala and Phe17Ala mutations changed the kinetics of both unfolding and refolding. Although the activated state of folding of the cold shock protein is overall native-like, individual side chains are still in a non-native environment.

Role of S-100 staining in differentiating leprosy from other granulomatous diseases of the skin

Since Mycobacterium leprae are rarely demonstrable in the tuberculoid spectrum of leprosy, a confirmatory diagnosis of leprosy can be made on the basis of finding active destruction of cutaneous nerves by granulomatous inflammation in a skin biopsy. Immunoperoxidase staining for S-100 protein, which is a marker for Schwann cells, was used to delineate nerves in lesional skin biopsies of 25 patients with tuberculoid and borderline tuberculoid leprosy as well as 15 controls with nonleprous granulomatous inflammation. Four different patterns of nerve damage were observed: infiltrated, fragmented, absent, and intact. All of the nonleprous granulomatous dermatoses showed only intact nerves, either inside or outside the granuloma, and so S-100 staining can be used to rule out leprosy.