Multiple rostral medullary nuclei can influence breathing in awake goats

The purpose of this study was to determine the effect on breathing of neuronal dysfunction in the retrotrapezoid (RTN), facial (FN), gigantocellularis reticularis (RGN), or vestibular (VN) nuclei of adult awake goats. Microtubules were chronically implanted to induce neuronal dysfunction by microinjection of an excitatory amino acid (EAA) receptor antagonist or a neurotoxin. The EAA receptor antagonist had minimal effect on eupneic breathing, but 8--10 days after injection of the neurotoxin, 7 of 10 goats hypoventilated (arterial PCO(2) increased 3.2 +/- 0.7 Torr). Overall there were no significant (P > 0.10) effects of the EAA receptor antagonist on CO(2) sensitivity. However, for all nuclei, > or =66% of the antagonist injections altered CO(2) sensitivity by more than the normal 12.7 +/- 1.6% day-to-day variation. These changes were not uniform, inasmuch as the antagonist increased (RTN, n = 2; FN, n = 7; RGN, n = 6; VN, n = 1) or decreased (RTN, n = 2; RGN, n = 3; VN, n = 2) CO(2) sensitivity. Ten days after injection of the neurotoxin into the FN (n = 3) or RGN (n = 5), CO(2) sensitivity was also reduced. Neuronal dysfunction also did not have a uniform effect on the exercise arterial PCO(2) response, and there was no correlation between effects on CO(2) sensitivity and the exercise hyperpnea. We conclude that there is a heterogeneous population of neurons in these rostral medullary nuclei (or adjacent tissue) that can affect breathing in the awake state, possibly through chemoreception or chemoreceptor-related mechanisms.

Severe anaphylaxis induced by latex as a contaminant of plastic balls in play pits

BACKGROUND

Latex causes anaphylaxis in specific contexts among children. We present 2 cases that show that severe reactions may occur in everyday circumstances with latex as a contaminant.

OBJECTIVE

Because 2 cases of severe reactions to latex suggested similar circumstances of exposure, we investigated the immediate environment in which episodes occurred.

METHODS

A 5-year-old girl presented to our casualty department with anaphylaxis after playing in a ball pit filled with approximately 10-cm diameter plastic balls in an American-style fast-food outlet. Two months later, a 9-year-old boy had severe anaphylaxis followed by an asthma attack with loss of consciousness while playing in the playpen of a different outlet belonging to the same company. Latex sensitization was confirmed in both cases by means of skin prick testing, latex glove skin prick testing, and 1-glove finger testing. Immunoblotting of elutions from a ball, the natural rubber latex foam pit lining, and its polyvinyl chloride sheet were performed.

RESULTS

In the girl's immunoblot high levels of IgE specific to Hev b 4, Hev b 7, and Hev b 2 were found. The boy's immunoblot showed positivity to Hev b 7. The polyvinyl chloride ball sample showed a high concentration of specific Hevea species allergen similar to that of the foam layer sample.

CONCLUSION

Severe anaphylaxis can result from contact with latex proteins as a contaminant, rather than as a component, of play area ball pits and therefore outside the reported settings. Emergency health care workers should be aware of this kind of risk. A latex-reduced environment might prevent potentially severe reactions in young customers of fast-food outlets.

[Rapid-detection GBM-ANCA ELISA. An emergency tool for the early diagnosis of type I and II rapidly progressive glomerulonephritis]

Rapidly progressive glomerulonephritides (RPGN) are forms of necrotizing glomerulonephritis associated with anti-glomerular basement membrane (anti-GBM) and anti-neutrophil cytoplasmic antibodies (ANCA) against the antigens proteinase-3 (anti-PR3) and myeloperoxidase (anti-MPO). RPGN have a course of rapid progression to renal failure. We compared the results from the semiquantitative ELISAs for anti-GMB antibodies, PR3-ANCA and MPO-ANCA and the indirect immunofluorescence technique (IIF) against a new rapid assay (30 minutes) for the same antibodies in patients with clinically suspected RPGN. The semiquantitative ELISAs for anti-GBM antibodies and PR3-ANCA and MPO-ANCA have a proven diagnostic significance in patients with RPGN I and III. There were no significant differences between the ANCA-GBM screening test and the results from the semiquantitative ELISAs (p > 0.05). We did not find significant differences between the results for PR3-ANCA and MPO-ANCA from the ANCA-GBM screening test with C-ANCA and P-ANCA IIF values (p > 0.05). We also corroborated that the ANCA-GBM screening test is a diagnostic tool for RPGN I and III as useful as the semiquantitative ELISAs and the IFF technique. The ANCA-GBM ELISA screening test is a tool as useful as the semiquantitative ELISA against anti-GBM antibodies for diagnosis of RPGN I. The comparison of the screening ELISA with the IIF technique and the semiquantitative ELISAs against PR3-ANCA and MPO-ANCA showed similar utility for diagnosis of RPGN III. The advantages of the new screening assay are that three antibodies are tested at the same time, yielding results in only 30 minutes.

Cerebral cortical blood flow during loss of consciousness induced by gravitational stress in rhesus monkeys

We investigated the influence of +Gz acceleration (head-to-foot inertial forces) onset on cerebral cortical blood flow (CBF) of rhesus monkeys to study the mechanisms underlying +Gz-induced loss of consciousness (G-LOC). CBF was measured through a chronic cranial window by laser-Doppler flowmetry and electrodes in contact with the dura mater were used to detect G-LOC (suppression of the cortical electrical activity). The animals were centrifuged up to +12 Gz with different G-onset rate until G-LOC occurred. G-LOC was preceded by a 2-5 s decrease in CBF. At G-LOC detection, CBF was not related to G-onset rate (mean CBF change: -76 +/- 9% of control value). We conclude that G-LOC results from cerebral ischemia rather than from mechanical stresses applied to the brain.

Suicide probability and psychological morbidity secondary to HIV infection: a control study of HIV-seropositive, hepatitis C virus (HCV)-seropositive and HIV/HCV-seronegative injecting drug users

BACKGROUND

Suicide ideation and psychological morbidity among HIV-positive patients has been the object of intense research. No study has investigated this area among injecting drug users (IDUs) infected with HIV and those infected with the hepatitis C virus (HCV), which has the same patterns of transmission of the HIV and may favour HIV replication and, possibly, HIV disease progression.

METHODS

In order to examine the prevalence and characteristics of suicide ideation and psychological morbidity associated with HIV and HCV infection in IDUs, a sample of HIV+ (n=81), HIV-/HCV+ (n=62) and HIV-/HCV- (n=152) subjects completed the Suicide Probability Scale (SPS), The Brief Symptom Inventory (BSI) and the Hospital Anxiety and Depression Scale (HADS).

RESULTS

No difference was found between the groups as far as the mean scores on SPS and the risk of suicide (no-low risk category: 70.7% HIV+, 56.09% HCV+, 65.6% HIV-/HCV-). Estimated psychological morbidity (BSI) (26.9% HIV+, 27.1% HCV+, 25.4% of HIV-/HCV-) and BSI and HADS scores were comparable across the groups.

CONCLUSIONS

Suicide ideation, psychological morbidity and anxiety and depression symptoms seemed not to be directly influenced by HIV-serostatus. Careful assessment of psychological symptoms and suicide ideas among IDUs, as a vulnerable segment of population at risk of HIV and HCV infections, needs to be routinely carried out in clinical settings.

Psychological factors and visual fatigue in working with video display terminals

OBJECTIVES

To examine the part played by psychological factors in complaints about visual health reported by banking officers who work at video display terminals (VDTs).

METHODS

Out of a population of 385 bank workers, a group of 212 subjects without organic visual disturbances (as determined by ophthalmological examination) who share a work environment and job duties was selected. Three questionnaires were administered to these subjects: (a) the NIOSH job stress questionnaire; (b) a questionnaire investigating subjective discomfort related to environmental and lighting conditions of the workplace; (c) a questionnaire on the existence of oculovisual disturbances. Correlation and multiple regression analyses were performed to examine for the presence of predictors of asthenopia.

RESULTS

Social support, group conflict, self esteem, work satisfaction, and underuse of skills were found to be predictors of visual complaints; social support played a part also as a moderating factor in the stress and strain model; this model accounted for 30% of the variance. Subjective environmental factors, although in some cases significantly correlated with asthenopia, were not found to be strong predictors of the symptoms.

CONCLUSIONS

Some part of the complaints about visual health reported by VDT workers are likely indirect expressions of psychological discomfort related to working conditions.

Effect of bioactive aldehydes on cell proliferation and c-myc expression in HL-60 human leukemic cells

Lipid peroxidation produces several toxic carbonyls, including biologically active aldehydes. In previous studies, we demonstrated that 4-hydroxynonenal (HNE), one of the major products of lipoperoxidation, inhibited growth and c-myc expression in K562 and HL-60 human leukemic cells. In this study, we compared the HNE effects with those of 4-hydroxyoctenal (HOE), 4-hydroxyundecenal (HUE; different lengths of the lipophilic tail), and the analogous aldehydes 2-trans-nonanal (lacking the OH group) and nonenal (lacking the OH group and the trans CC double bond), on HL-60 cell proliferation and c-myc expression. HUE and HOE inhibited growth and c-myc expression in a dose-dependent fashion, with an effectiveness comparable with that of HNE, whereas 2-nonenal and nonanal did not affect these parameters. Our results showed that different aldehydes produced from lipid peroxidation may contribute to growth inhibition by c-myc downregulation and that the molecular features involved seem to be the hydroxy group and the trans CC double bond.

Antibodies elicited by naked DNA vaccination against the complementary-determining region 3 hypervariable region of immunoglobulin heavy chain idiotypic determinants of B-lymphoproliferative disorders specifically react with patients' tumor cells

Several reports have suggested that the mechanism of protection induced by antiidiotypic vaccination against low-grade lymphoproliferative disorders is likely to be antibody mediated. Here we test the hypothesis that DNA vaccination with the short peptide encompassing the complementary-determining region 3 hypervariable region of immunoglobulin heavy chain (VH-CDR3) may elicit a specific antibody immune response able to recognize the native antigens in the form required for therapy. As a test system, we used the VH-CDR3 sequences derived from two patients with non-Hodgkin's B lymphomas (PA, AS) and one patient with hairy cell leukemia (BA) to immunize outbred Swiss mice. This experimental model could mimic a clinical setting in which different patients present distinct HLA haplotypes. Individual tumor-specific VH-CDR3 sequences were amplified by a two-step procedure and directly cloned into multigenic plasmid vectors (pRC100 and derived) with and without mouse interleukin 2 (mIL-2). Each tumor-specific sequence was characterized by sequencing. Female Swiss mice were vaccinated i.m. with plasmids expressing the tumor-specific VH-CDR3 sequence alone (pRC101-PA), mIL-2 plus the VH-CDR3 sequence (pRC111-PA), or a different unrelated antigen (NS3 of hepatitis C virus; pRC112), the sole mIL-2 (pRC110), and the empty plasmid (pRC100). Boost injections were performed at 3 and 16 weeks from the first vaccination, and sera were drawn before each vaccination and at 6, 9, and 19 weeks. Induction of anti-VH-CDR3s antibodies in the sera and their ability to recognize native antigens on patients' tumor cells were evaluated by FACS analysis. Up to 56% (n = 25) of mice vaccinated with pRC111-PA plasmid and 20% (n = 15) of mice vaccinated with pRC101-PA developed a specific immune response that was maintained throughout 19 weeks of observation in 40% of pRC111-PA-vaccinated mice. No response was detected in sera obtained from mice vaccinated with the other plasmids (n = 45). pRC111-PA injection s.c. was less effective (13%, n = 15) than i.m. injection (53%, n = 15). Indeed, we demonstrated that antibodies elicited by naked DNA vaccination against three different patient-derived VH-CDR3 peptides (pRC111-PA or BA or AS) readily reacted with binding epitopes on the idiotypic proteins expressed on the surface of tumor cells derived from each patient; 60, 40, and 40% of, respectively, PA-, BA-, and AS-vaccinated mice developed specific antibodies. No cross-reactivity was detected among the three different CDR3s against tumor cells derived from the other two patients. The outbred mouse strategy confirmed the significant matching potential of three different VH-CDR3 peptides to be efficaciously presented through different MHCs. We conclude that individual VH-CDR3 DNA vaccination can result in a potentially effective specific immune response against non-Hodgkin's B lymphoma cells by a rapid and low-cost therapeutic approach.

Comparison of MRI, EEG, EPs and ECD-SPECT in Wilson's disease

OBJECTIVES

The purpose of this study is to evaluate the efficiency of a few methodologies in detecting anatomo-functional brain abnormalities in patients with Wilson's disease.

MATERIALS AND METHODS

Twenty-three patients with Wilson's disease underwent almost simultaneously brain magnetic resonance imaging (MRI), computerized electroencephalography (EEG), multimodal evoked potentials (EPs) and ECD single photon computerized tomography (SPECT) evaluation. The clinical picture was of the neurologic type in 8 patients and of the hepatic type in 15.

RESULTS

MRI was abnormal in 7 patients with neurological manifestations. The EPs proved pathologic in 7 neurologically symptomatic patients and in 4 cases with hepatic form. These results agree with those reported in other case studies. The EEG records were abnormal only in 3 cases. Nevertheless, the most interesting finding of this study is the particular frequency (86%) of diffuse or focal decrease of ECD uptake shown by brain SPECT.

CONCLUSION

We highlight the use of this interesting procedure in the therapeutic monitoring of this disease.

Non-confluent pulmonary arteries in a patient with pulmonary atresia and intact ventricular septum: ? A 5th aortic arch with a systemic-to-pulmonary arterial connection

Major abnormalities of pulmonary circulation are uncommon in the patient with pulmonary atresia and intact ventricular septum. Non-confluent pulmonary arteries have only rarely been described in this setting. In this case report, we describe a patient in whom the pulmonary arteries are non-confluent, with the right pulmonary artery supplied through a right-sided arterial duct, and the left pulmonary artery most likely through a fifth aortic arch, thus providing a systemic-to-pulmonary arterial connection. We discuss the various forms of non-confluent pulmonary arteries in the setting of pulmonary atresia and intact ventricular septum.

Maternity advice survey: sleeping position in Eastern Europe. MAS Study Group for WHO EURO region

AIM

To identify hospitals in Eastern Europe promoting front infant sleeping position.

METHODS

Questionnaires were distributed to maternity units in 22 countries during July to November 1999.

RESULTS

A total of 489 hospitals in 20 countries responded. Preferred position in normal care units was back (26.6%), front (1. 8%), side (65%), or combination/none (6.6%). Corresponding recommendations at discharge were 17.4%, 3.5%, 73%, and 6.1%.

[Permanent central venous catheters for dialysis. The situation in Piedmont-Aosta Valley]

BACKGROUND

Permanent central venous catheters for hemodialysis have become increasingly important as vascular accesses for extracorporeal dialysis. The aim of this study was to evaluate the prevalence and various aspects of these catheters in the chronic dialysis population in Piedmont and Aosta Valley on 30-6-1998 using a multiple-choice questionnaire.

METHODS

A total of 2389 patients were receiving chronic hemodialysis. Permanent central venous catheters were present in 6.2% of the population (149 patients), arteriovenous fistulas in 83.1%, vascular prostheses in 9.3% and temporary catheters in 1.4%. The site chosen for permanent catheters was the internal jugular vein in 88.6% of cases, the subclavian vein in 8.7% of cases and the femoral vein in 2.7% of cases. The double catheter is the most frequently used. In 76% of centres catheters are positioned by nephrologists. Thrombosis prophylaxis is performed in 98% of cases with heparin and the most frequently used disinfectant to dress the cutaneous exit is iodopovidone.

RESULTS

This study highlights the important role played by permanent catheters. The double catheter was used in 64.4% of the entire population, confirming the greater efficiency of these catheters as reported in the literature. Operating autonomy is relative in 76.2% of centres where catheters are positioned by nephrologists who often use the collaboration of other specialists.

CONCLUSIONS

The authors stress the need to reflect on the use of iodopovidone is to dress the cutaneous exit of catheters since this disinfectant is contraindicated by one of the largest manufacturers of silicone catheters owing to its harmful medium long-term effects.

The usefulness of conventional and echo colour Doppler sonography in the differential diagnosis of toxic multinodular goitres

OBJECTIVE

To assess the potential role of conventional sonography and colour flow Doppler (CFD) sonography (CFDS) in the differential diagnosis of toxic multinodular goitres.

SUBJECTS AND METHODS

We investigated 55 patients with untreated hyperthyroidism (24 with typical toxic diffuse goitre of Graves' disease (Group A); 26 with multinodular goitre (Group B); and five with single toxic adenoma (Group C); 22 euthyroid subjects (12 with non-toxic multinodular goitre (Group D) and ten normal subjects (Group E)) were included as controls. In all cases free thyroxine, free tri-iodothyronine, TSH, TSH receptor antibodies (TRAb), anti-thyroperoxidase antibody, anti-thyroglobulin antibodies and anti-thyroid microsomal antibodies were determined and a [(99m)Tc]pertechnetate thyroid scan was performed.

RESULTS

Patients with toxic multinodular goitre displayed two different CFDS patterns: 18 patients (Group B-1) had nodules with normal vascularity surrounded by diffuse parenchymal hypoechogenicity with markedly increased CFD signal and maximal peak systolic velocity (PSV) (a pattern similar to Group A patients with Graves' disease); eight patients (Group B-2) had increased intra- and perinodular CFD signal and PSV with normal extranodular vascularity (a pattern similar to that found in Group C patients with single toxic adenoma). Patients of Group B-1 showed a proportion of clinically evident thyroid ophthalmopathy, positive TRAb and other thyroid autoantibodies similar to that observed in Group A patients, while no evidence of thyroid autoimmunity was found in Group B-2. Sixteen out of 18 (89%) patients from Group B-1 displayed a scintiscan pattern of diffuse uneven radionuclide distribution, while seven out of eight (87.5%) of those from Group B-2 had localized uptake in multiple discrete nodules. Taken together, these data strongly suggest that Group B-1 mostly represents patients with the multinodular variant of Graves' disease, while Group B-2 represents patients with non-autoimmune toxic multinodular goitre.

CONCLUSIONS

This study shows that combined conventional sonography and CFDS may easily distinguish nodular variants of Graves' disease from non-autoimmune forms of toxic multinodular goitre and confirms the clinical usefulness of this technique in the first-line evaluation of hyperthyroid patients.

Assessment of peripheral blood lymphocyte subsets in idiopathic myelofibrosis

The objective of this study was to contribute to a better characterization of the immunological profile of idiopathic myelofibrosis (IM) at presentation by analysing the blood lymphocyte subsets and their possible correlations with other disease features. Absolute blood lymphocytes and lymphocyte subsets were assessed in 31 IM patients, compared with those from 34 healthy individuals, and correlated with the patients' main clinical, hematological and bone marrow histologic features. The mean lymphocyte count of the IM patients was 1.1 (SD 0.6) x 10(9)/L, versus 1.6 (SD 0.49) x 10(9)/L in controls (p = 0.0006), with 24 of the 31 patients (77.4%) showing lymphocytopenia (< 1.5 x 10(9)/L). IM patients had significantly lower counts of CD3, CD4, CD8, and CD3 -/ CD56+ cells, and significantly higher CD3 +/CD56 + lymphocyte counts. Although no significant differences were found between patients and controls with regard to CD19+/CD5+ cell counts, increased CD5 + B-cell lymphocytes were observed in three IM patients. In one of the latter patients, Ig gene rearrangement analysis of the heavy chain gene demonstrated such a subpopulation to be clonal, but the patient did not develop features of chronic lymphoid leukemia during a 5-yr follow-up. No correlation was found between the patients' blood lymphocyte counts and other disease features. We conclude that most IM patients have absolute lymphopenia, decreased T cells and increased cytotoxic T cells at diagnosis, and 10% of them show an increased CD5 + B-cell subpopulation.

A longitudinal study of T1 hypointense lesions in relapsing MS: MSCRG trial of interferon beta-1a. Multiple Sclerosis Collaborative Research Group

BACKGROUND

T1 hypointense lesions (T1 black holes) are focal areas of relatively severe CNS tissue damage detected by MRI in patients with MS.

OBJECTIVE

To determine the natural history of T1 hypointense lesions in relapsing MS and the utility of T1 hypointense lesions as outcome measures in MS clinical trials.

METHODS

MR studies were from the Multiple Sclerosis Collaborative Research Group trial. Longitudinal results are reported in 80 placebo- and 80 interferon beta-1a (IFNbeta-1a)-treated patients with mild to moderate disability relapsing-remitting MS.

RESULTS

There was a small but significant correlation between T1 hypointense lesion volume and disability at baseline and on trial (r = 0.22, r = 0.28). In placebo patients there was a 29.2% increase in the mean volume of T1 hypointense lesions (median 124.5 mm3) over 2 years (p < 0.001 for change from baseline), as compared to an 11.8% increase (median 40 mm3) in the IFNbeta-1a-treated patients (change from baseline not significant). These treatment group comparisons did not quite reach significance. The most significant contributor to change in T1 hypointense lesions was the baseline number of enhancing lesions (model r2 = 0.554). Placebo patients with more active disease, defined by enhancing lesions at baseline, were the only group to show a significant increase in T1 hypointense lesion volume from baseline.

CONCLUSION

The development of T1 hypointense lesions is strongly influenced by prior inflammatory disease activity, as indicated by enhancing lesions. These results suggest that treatment with once weekly IM IFNbeta-1a (30 mcg) slows the 2-year accumulation of these lesions in the brain.

Tracheostomy care

The author considers airway maintenance in the care of adult patients by providing a clinical overview of the pre- and post-operative requirements of tracheostomy care, including complications and the longer term implications that can arise immediately after tracheostomy surgery.

[Crossed aphasia: description of a case]

We describe a new case of crossed aphasia in a right-handed patient with a right hemispheric lesion. A right-handed man, 76 year-old, developed a sudden left hemiparesis with sensitive impairment and mutism. He has neither family history of left handeness or ambidexterity or vascular risk factors. CT cerebral scan showed a large infarct of the middle cerebral artery on the right side, with haemorrhagic suffusion. Cerebral MRI and EEG-cartography confirmed the indemnity of the left hemisphere. Aphasia studies confirmed a mutism with spared verbal comprehension, but alexia was present. A year later, left hemiparesis was recovered but aphasia remained. Crossed aphasia is rarely seen. It is caused by a right hemispheric lesion in right-handed subjects. Fluency is most commonly impaired. At onset, mutism is the common symptom, which evolves to expressive aphasia. Several hypothesis have been raised about the possible mechanisms involved. The few number of PET or SPECT studies performed in these patients have disclosed extensive areas of hypometabolism in the right hemisphere, that exceed the size of the image observed with CT scan or MRI.