Sexual and asexual development of Cryptosporidium parvum in five oocyst- or sporozoite-infected human enterocytic cell lines

The human enterocytic cell lines Caco-2, HT29, HCT8 and the Caco-2 clones TC7 and PF11 were studied for their ability to support Cryptosporidium parvum development. Following the addition in cultures of either oocysts or excysted sporozoites, immunofluorescent and transmission electron microscopy revealed the presence of all stages of the parasite life cycle by both procedures, and no difference in the ratio of infected cells was found among cell lines. More oocysts were seen in cell monolayers infected with oocysts than with sporozoites (p < 0.0001). The number of meronts observed was the same after either oocysts or sporozoites inoculation. Data suggest that the two methods yield a same cell infection rate.

Development of a Chemically Defined Medium for the Growth of Leuconostoc mesenteroides

A chemically defined medium for the growth of Leuconostoc mesenteroides was developed. This medium contained lactose, Mn(sup2+), Mg(sup2+), 12 amino acids, eight vitamins, adenine, uracil, and Tween 80. We showed the beneficial effect of aerobic conditions on growth and that potassium phosphate (135 mM) is a suitable buffer. The growth rate in this medium was 0.85 (plusmn) 0.10 h(sup-1) for the six strains examined, and cell densities up to 3.5 x 10(sup9) CFU/ml were attained.

The Provo multicenter early high-frequency oscillatory ventilation trial: improved pulmonary and clinical outcome in respiratory distress syndrome

OBJECTIVE

To compare the hospital course and clinical outcome of preterm infants with respiratory distress syndrome treated with surfactant and managed with high-frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation (CV) as their primary mode of ventilator support.

DESIGN

A prospective randomized clinical trial.

SETTING

Three community-based level III neonatal intensive care units.

SUBJECTS

A total of 125 neonates who were 35 weeks or less estimated gestation requiring intubation and assisted ventilation for respiratory distress syndrome with arterial to alveolar oxygen ratio less than .50.

INTERVENTIONS

Patients were randomized to continue CV (61 patients) or be changed to HFOV (64 patients) after exogenous surfactant administration (100 mg/kg). HFOV was used in a strategy to promote lung recruitment and maintain lung volume. Protocol respiratory care guidelines were followed; otherwise routine care was provided by each neonatal intensive care unit.

MEASUREMENTS AND MAIN RESULTS

No differences were noted in demographic features between the two study groups. The study population birth weight was 1.51 +/- .47 kg (mean +/- SD), gestational age was 30.9 +/- 2.5 weeks, and study entry age was 2 to 3 hours. Patients randomized to HFOV demonstrated the following significant findings compared with CV-treated patients: vasopressor support was less intensive; surfactant redosing was not as frequent; oxygenation improved more rapidly and remained higher during the first 7 days; fewer infants required prolonged supplemental oxygen or ventilator support; treatment failure was reduced; more patients survived without chronic lung disease at 30 days; need for continuous supplemental oxygen at discharge was less; frequency of necrotizing enterocolitis illness was lower; there were fewer abnormal hearing tests; and hospital costs were decreased. No differences were seen between the two study groups in the frequency or severity of patent ductus arteriosus, air leak, retinopathy of prematurity, or intraventricular hemorrhage. Length of hospital stay and survival to discharge were similar for HFOV- and CV-treated infants.

CONCLUSIONS

When used early with a lung recruitment strategy, HFOV after surfactant replacement resulted in clinical outcomes consistent with a reduction in both acute and chronic lung injury. Benefit was evident for preterm infants both less than or equal to 1 kg and more than 1 kg. In addition, early HFOV treatment may have had a more global effect on patient health throughout the hospitalization, resulting in reduced morbidity and decreased health care cost.

Crescentic glomerulonephritis in juvenile chronic arthritis

Juvenile chronic arthritis (JCA) was diagnosed in 2 young girls. In one of them, antinuclear antibodies (ANA) were strongly positive during the course of erosive polyarthritis. After 5 years followup, severe renal insufficiency occurred. Antineutrophil cytoplasmic antibodies (ANCA) were positive with a perinuclear pattern on indirect immunofluorescence (IIF) and antimyeloperoxidase (MPO) specificity. Renal biopsy showed severe crescentic glomerulonephritis without significant deposits on IIF. Treatment consisted of prednisone and monthly intravenous cyclophosphamide pulse. Renal failure worsened and hemodialysis was necessary. A 2nd patient was referred for polyarthritis with positive rheumatoid factors without positive ANA. The presence of microscopic hematuria led to the discovery of crescentic glomerulonephritis with positive ANCA of anti-MPO specificity. At latest examination, after prednisone for 10 months and azathioprine for 6 months, the patient had moderate proteinuria with normal renal function. These observations emphasize that in juvenile onset chronic polyarthritis, renal microscopic angiitis with ANCA of anti-MPO specificity may occur.

Neuroendocrine primary small cell carcinoma of the breast. Report of a case and review of the literature

One case of breast neuroendocrine primary small cell carcinoma with light microscopic and immunohistochemical findings is reported. The patient died of unrelated disease 21 months after diagnosis and treatment by modified radical mastectomy, radiotherapy and subsequent chemotherapy. Immunohistochemical studies revealed cytokeratin and neuroendocrine markers (chromogranin, neuron-specific enolase) immunostaining on tumoral cells. Expression for neuropeptides (met-enkephalin, leu-enkephalin, beta-endorphin) and CALLA antigen was found. Based on this case report and six other previously reported cases, breast neuroendocrine primary small cell carcinoma appears to be a very aggressive tumor for which no firm conclusions regarding treatment can be drawn.

Microcystin-LR induced an inhibition of protein synthesis in isolated rat hepatocytes

The effect of microcystin-LR, an inhibitor of protein phosphatases PP1 and PP2A, was studied on protein synthesis by measuring the incorporation of labelled amino acid into protein in isolated rat hepatocytes. Microcystin-LR inhibited protein synthesis in the first minutes of the incubation period, and half-maximum effect was obtained at about 60 nM. Such an inhibition was also observed in the presence of different protein phosphatase inhibitors, i.e. okadaic acid, calyculin A and microcystin-RR. This effect was observed in whole hepatocytes, in the supernatant of the post-mitochondrial fraction and in the microsomal fraction. It was independent of a substrate supply and of the labelled amino acid used. Furthermore, this inhibition preceded the previously reported glucose-6-phosphatase activation induced by microcystin-LR [Claeyssens, Chédeville and Lavoinne (1993) FEBS Lett. 315, 7-10].

Changes in rat atrial ANF granules induced by hindlimb suspension

It is well known that the heart releases a factor called ANF (atrial natriuretic factor) or ANP (atrial natriuretic peptide) capable of inducing rapid diuretic and natriuretic actions. This factor is stored in secretory granules mainly located in myocytes in both atria. The main secretory stimulus is the distention of the atrial cavity resulting, for example, from enhanced venous return. However, the cellular events which occur after the stimulation remain to be clarified. The aim of this investigation was to study the intra-cellular events preceding the ANF release, using the rat hindlimb suspension as model of stimulation. In this model, Wistar rats were placed in a 30 degrees anti-orthostatic position and a blood shift towards the heart was obtained. Different durations (1/4 h, 1/2 h, 3/4 h, 1 h, 2 h and 6 h) were studied. The ANF plasma level was investigated by Radio Immuno Assay and granule immunoreactivity was measured by counting gold particles on micrographs. The ANF plasma level was significantly increased (+60%) after 1 h of suspension. The response was transient and then decreased to basal values. Morphological criteria established at the beginning of this study, and measured throughout the experiment, were found transiently modified after suspension. The surface of the perinuclear area was transitory enlarged by 36% 30 min after suspension. Moreover, in the same time immunoreactivity of the secretory granules was enhanced without changes in granule size. These results suggest an increase in the ANF synthesis and storage in the granules during the stimulation. However, the cellular regulatory mechanism of the ANF synthesis which could explain the transitory aspect of these events, requires further investigation.

Suppression of HLA-specific alloantibodies by high-dose intravenous immunoglobulins (IVIg). A potential tool for transplantation of immunized patients

Renal transplantation in patients presenting end-stage renal failure can be hampered by the presence of alloantibodies against HLA antigens. In 4 out of 5 patients with HLA-specific alloantibodies waiting for a renal allograft, treatment with high-dose i.v. Ig resulted in a prolonged suppression (over 3 months) of most of the panel-reactive anti-HLA antibodies (PRA). Intravenous polyclonal human Ig (IVIg) and F(ab')2 fragments from IVIg inhibited the binding of patients' plasma and IgG fractions to peripheral blood lymphocytes from normal donors as well as their cytotoxicity, suggesting that the in vivo effect of IVIg was mediated by the presence, in the IVIg preparation, of anti-idiotypes directed against idiotypes borne on the anti-HLA antibodies. Thus, treatment with IVIg can be a valuable tool toward the transplantation of immunized patients.

Glomerulonephritis in chronic lymphocytic leukemia and related B-cell lymphomas

We retrospectively analyzed clinical presentation, immunopathological data and renal outcome in 13 patients with glomerulonephritis (GN) and chronic lymphocytic leukemia (CLL) or related diffuse well-differentiated lymphocytic lymphoma (WDLL) of B-cell lineage. B-cell proliferation and glomerulopathy were simultaneously diagnosed in seven of the 13 patients. Nephrotic syndrome was observed in nine patients. Serum creatinine was elevated (greater than 120 mumol/liter) in 10 patients and exceeded 400 mumol/liter in three patients. A clear cut relationship between GN and hematologic disease could be established in nine cases: five patients had MPGN caused by type I or type II cryoglobulinemia; two had MPGN or mesangial hypertrophy with circulating and deposited noncryoprecipitating monoclonal IgG K and IgM K, respectively; in the two remaining patients, monotypic IgG K glomerular deposits exhibiting fibrillary organization were observed in association with MGN or MPGN, despite the absence of circulating M-component by immunofixation. The pathophysiologic link between glomerular lesions and B-cell proliferation was further evidenced by effectiveness of specific treatment of the malignancy by chlorambucil. This drug, used in the absence of steroids, induced complete remission of nephrotic syndrome in the five patients to whom it was given. Moreover, in the five patients with creatininemia greater than 200 mumol/liter who received chemotherapy, substantial improvement in renal function was observed. These overall data demonstrate that the occurrence of GN in B-CLL and related lymphoma is not fortuitous, and testify to the paraneoplastic nature of glomerular involvement mediated by deposition and possibly processing of cryoprecipitating or noncryoprecipitating M-components.

Parotid gland abnormality found in children seropositive for the human immunodeficiency virus (HIV)

Out of our series of 24 children seropositive for the Human Immunodeficiency Virus (HIV), parotid gland enlargement was noted in 4 children with AIDS-related complex (ARC) presenting also a Lymphocytic Interstitial Pneumonitis (LIP) on their chest radiographs. The ultrasound (US) aspect of the parotid gland suggests acinar enlargement (suggesting the presence of lymphocytic infiltration). The aspect displayed in the parotid mirrors the process developing in other areas (lungs, liver, spleen, lymph-nodes), i.e. a syndrome of lymphocytic (CD8) proliferation present at the stage of ARC.

In vivo 1H NMR spectroscopy of an intracerebral glioma in the rat

High-resolution 1H surface coil NMR spectroscopy (MRS) was used to evaluate in vivo the cerebral metabolism changes in rat brain induced by a glial tumor growing in situ. Tumor cells (C6 glioma cells) were stereotaxically placed in the right hemisphere superficially. 1H MRS was performed using 5-mm surface coils implanted over the right hemisphere and the water was suppressed using a binomial sequence. As the intracerebral tumor size increased, there was a marked decrease in the N-acetyl aspartate level and an increase in the 1.3 ppm peak. Edition of this peak showed that lactate increased but lipids increased much more than lactate. Moreover the ratio between the choline-phosphocholine and creatine-phosphocreatine peaks changed. This study demonstrates that high-resolution surface coil 1H MRS can be used to monitor changes in metabolism associated with growth of an experimentally induced rat brain tumor in situ.

Disseminated BCG in HIV infection

A boy, born to a mother with AIDS related complex, was immunised with BCG on the 10th day of life. At the age of 4 months he presented with a local enlarged lymph node, fever, hypotonia, and diarrhoea. Mycobacterium bovis, BCG strain, was grown from the lymph node and cerebrospinal fluid; this proved dissemination.

Etude de l'évolution des populations bactériennes d'origine tellurique, entérique et marine dans des systèmes planctoniques soumis à une pollution urbaine, traitement mathématique des données

A study of the comparative distribution of different types of bacterial populations in the sea area where the city of Marseille rejects its waste water shows that, when in contact with the marine environment, a great part of the allochthonic bacterial population undergoes physiological stress expressed by an abrupt reduction of the effectives and by weak values of the energetic charge.The presence of coliforms and streptococci in waste water lens, at important distances from discharging conduits, shows the possibility of a large diffusion for a fraction of the bacterial populations that withstand the initial stress.From mathematical analyses, an inverse correlation is revealed between detergents and the bacterial population as a whole, and between phenols and various allochthonic bacterial populations.The above results were evidenced through a sampling strategy based upon a 24-h-cycle study and a search for mathematical correlations between several biological, chemical, and physical parameters. [Translated by the journal]

[Development of bacterial populations of telluric, enteric, and marine origin in planktonic systems exposed to urban pollution; mathematical data analysis]

A study of the comparative distribution of different types of bacterial populations in the sea area where the city of Marseille rejects its waste water shows that, when in contact with the marine environment, a great part of the allochthonic bacterial population undergoes physiological stress expressed by an abrupt reduction of the effectives and by weak values of the energetic charge. The presence of coliforms and streptococci in waste water lens, at important distances from discharging conduits, shows the possibility of a large diffusion for a fraction of the bacterial populations that withstand the initial stress. From mathematical analyses, an inverse correlation is revealed between detergents and the bacterial population as a whole, and between phenols and various allochthonic bacterial populations. The above results were evidenced through a sampling strategy based upon a 24-h-cycle study and a search for mathematical correlations between several biological, chemical, and physical parameters.