Effects of calcineurin inhibitors on an in vitro assay for chronic urticaria

BACKGROUND

Chronic urticaria is a common skin disorder, which causes considerable morbidity. In approximately 40% of cases, patients have an autoimmune disorder in which functional antibodies cause degranulation of mast cells and basophils, and C5a complement augments this in varying amounts from patient to patient. Since the calcineurin inhibitor ciclosporin has been used in chronic autoimmune urticaria, we examined the effect of ciclosporin and other drugs on the release of histamine from basophils when stimulated by sera from patients with chronic autoimmune urticaria.

METHODS

Leucocytes from healthy donors were isolated and incubated in varying concentrations of ciclosporin, ascomycin, methotrexate, diphenhydramine or hydroxyzine for 30 min prior to stimulation with serum from urticaria patients known to have functional immunoglobulin (Ig)G antibodies directed against the alpha subunit of the IgE receptor. Histamine release was then measured.

RESULTS

Pre-incubating cells with ciclosporin and ascomycin produced dose-dependent inhibition of histamine release when cells were stimulated by sera of urticaria patients, by purified IgG from these sera, but not by C5a. Inhibition was not prevented by C5a receptor blocking antibodies. No inhibition was seen with methotrexate, diphenhydramine or hydroxyzine.

CONCLUSIONS

This is the first demonstration of inhibition of histamine release by calcineurin inhibitors employing sera of patients with chronic autoimmune urticaria. These drugs may work by interfering with intracellular signalling in cells following cross-linking of the IgE receptor, but not following stimulation of the C5a receptor.

Preinjury Behavioral and Emotional Problems Among Pediatric Burn Patients

Standardized behavior rating scales have been used in the routine care of children during medical visits because they provide an objective, norm-based index for the child's behavioral functioning. The purpose of this study was to examine behavior problems among children (aged 2.5-18 years) with burn injuries using the Behavioral Assessment System for Children, a multi-informant system of standardized rating scales that assesses clinical and adaptive behavior areas. Parents and youth (ages 8-18) completed the Behavioral Assessment System for Children with reference to the pediatric patient's behavioral functioning before hospital admission for a burn injury. In total, data were collected on 94 children. Results suggested that a substantial portion of the sample endorsed significantly elevated levels of behavioral difficulties across a broad range of problem behaviors. On the basis of parent report, preschoolers exhibited concerns related to hyperactivity, anxiety, aggression, and attention problems, whereas school-aged children were reported to have these same concerns as well as depression and conduct problems. Twenty percent of our adolescent sample (ages 12-18 years) were described to be experiencing even more internalizing and externalizing behavior problems relative to the two groups of their younger counterparts. Boys were found to contribute to the cause of their burn injury significantly more often than girls. The strengths, limitations, and clinical implications of our findings are discussed.

Assessment of the role of heparan sulfate in high molecular weight kininogen binding to human umbilical vein endothelial cells

The assembly and activation of the kinin forming system components on human umbilical vein endothelial cells (HUVEC) have been studied in great detail. Proteins such as gC1qR, cytokeratin-1 and u-PAR have been identified to be responsible for Zn2+-dependent binding of high molecular weight kininogen (HK) to HUVEC. Heparan sulfate has also been shown to have a major role in Zn2+-dependent binding of HK to the endothelial cell line, Ea.hy 926. In this study, we have analyzed the possible contribution of heparan sulfate to high molecular weight kininogen binding to HUVEC using multiple approaches. The presence of heparan sulfate on HUVEC was analyzed by staining with an antibody specific for heparan sulfate. Incubation of the cells with bacterial heparinases removed the heparan sulfate from the cell surface to the level seen with a control antibody, however, the Zn2+-dependent binding of HK was not affected. Further, blocking of heparan sulfate with a specific antibody to heparan sulfate even after digestion with heparinases did not reduce HK binding whereas antibodies to the proteins gC1qR and cytokeratin-1 consistently reduced the binding of HK to the endothelial cells. The binding intensities of FITC-labeled HK were similar in heparinase-treated and -untreated HUVEC. The rate of kallikrein formation by the assembly of factor XII, HK and PK were similar in both heparinase-treated and non-treated HUVEC. All of these data indicate that heparan sulfate does not contribute significantly to HK binding to HUVEC.

[Guideline for in vivo- and in vitro procedures for thyroid diseases (version 2)]

The version 2 of the guideline for diagnostic standards of thyroid disorders is an update of the guideline published in 1999 and describes standards of in vitro and in vivo procedures. The following statements are modified: In vitro procedures: When measurement of the TSH-receptor antibodies is indicated, the guideline recommends the use of a second generation assay (recombinant human TSH-receptor as antigen). The functional assay sensitivity for the measurement of thyroglobulin should reach a value < or =1 ng/ml. Molecular genetic tests (RET proto-oncogene) are indicated in patients with a newly diagnosed medullary thyroid cancer and in the relatives of patients with hereditary medullary thyroid cancer. In vivo procedures: The sonographic examination should use a probe with a frequency of at least 7.5 MHz. Indications for the thyroid scintigraphy: nodule size > or =1 cm in diameter, autonomous goitre/nodule with clinical or subclinical hyperthyroidism, necessity of a differentiation between Graves' disease and chronic lymphocytic thyroiditis, therapy control after a definitive treatment and - in individual cases - the follow-up of untreated autonomous nodules.

Follow-up of perfusion defects in pulmonary perfusion scanning after pulmonary embolism: are we too careless?

Persisting perfusion defects may still be found in pulmonary perfusion scintigraphy months or years after pulmonary embolism. The aim of this study was to investigate the rate of persisting perfusion defects and the pattern of scintigraphic follow-up of patients after pulmonary embolism. Only those patients were included into our study who received pulmonary perfusion scintigraphy between 1991 and 1999, and who had perfusion defects including at least one whole segment. These perfusion defects were considered as persisting perfusion defects if unchanged over at least 1 year. From 3640 patients examined, 451 (12.4%) had perfusion defects meeting the criteria of this study. Of those, 129 (28.6%) received a scintigraphic follow-up. In 62 patients (48.1%), a reperfusion of the defects was found. In 38 patients (29.5%), the defects persisted within a follow-up period of up to 12 weeks. However, no pulmonary perfusion scintigraphy was performed thereafter. Out of the 129 patients receiving a scintigraphic follow-up, only 29 (22.5%) had a follow-up over more than 1 year, 19 of those had persisting perfusion defects. It is concluded that our data show an inadequate scintigraphic follow-up of patients with pulmonary embolism which may lead to unnecessary anticoagulant treatment if persisting perfusion defects are misinterpreted as fresh pulmonary embolism. In many cases, there was no further follow-up even if reperfusion of the defects was lacking in early follow-up.

[Family planning among teenage mothers in a Cameroonian centre]

This study was carried out in Yaounde (Cameroon) in 1995 to determine the knowledge, attitude and behaviour of teenage mothers towards family planning. The study was based on a questionnaire administered at household level drawn from previously determined clusters. It was accomplished by recruiting 462 teenage mothers with ages ranging from 14 to 19 years and who had 1 to 3 children. On the whole, 93.9% had heard of family planning, 72.5% had heard of family planning centres, but only 43% had been to one of these centres at least once. With regards to contraceptive prevalence, 62.1% affirmed the use of a contraceptive method at the time of the study with periodic abstinence being the most widely used (35.9%). Besides the common methods, some teenage mothers made use of herbal concoctions and vaginal douching, sometimes with permanganate or the taking of tablets. Nineteen per cent of respondents had had between one and four episodes of induced abortion. According to these teenagers, the ideal average age for first delivery is 19.7 +/- 2.5 years, whereas that of nubility is 22.8 +/- 3.3 years, a difference of 3 years. This suggests that on the whole, teenage mothers believe that first delivery must precede marriage.

Activation of the plasma kinin forming cascade along cell surfaces

Proteins of the plasma kinin-forming cascade bind to endothelial cells and activation of the cascade can be initiated along the surface. The light chain of high molecular weight kininogen (HK) (domain 5) and factor XII bind to gC1qR, the heavy chain of HK (domain 3) binds to cytokeratin 1 and the interactions are zinc dependent. Prekallikrein binds to domain 6 of HK. Antisera to gC1qR and cytokeratin 1 inhibit binding and activation. Incubation of normal plasma with endothelial cells leads to gradual conversion of prekallikrein to kallikrein, while plasma deficient in factor XII or HK are inactive within a 2-hour time frame. Thus factor XII is critical for activation to proceed. Augmentation of these reactions may occur when C1 inhibitor is functionally deficient or with ACE inhibitors which also inhibit kininases.

Factor XII-dependent contact activation on endothelial cells and binding proteins gC1qR and cytokeratin 1

Although proteins of the kinin-forming pathway are bound along the surface of endothelial cells, the mechanism of activation of this proteolytic cascade is unclear. Endothelial cell surface proteins, gC1qR and cytokeratin 1, are capable of binding Factor XII and high molecular weight kininogen (HK) in a zinc-dependent reaction thus we considered the possibility that these proteins might catalyze initiation of the cascade. Incubation of Factor XII, prekallikrein, and HK with gC1qR or cytokeratin 1 leads to a zinc-dependent and Factor XII-dependent conversion of prekallikrein to kallikrein. We also demonstrate that normal plasma is capable of activating upon interaction with the cells whereas plasma deficient in Factor XII, prekallikrein and HK do not activate. Normal plasma activation was inhibitable by antibody to gC1qR and cytokeratin 1. Thus, gC1qR and cytokeratin 1, represent potential initiating surfaces for activation of the plasma kinin-forming cascade and may do so as a result of their expression along cell surfaces.

Activation of the kinin-forming cascade on the surface of endothelial cells

Activation of the plasma kallikrein-kinin forming cascade takes place upon incubation with human umbilical vein endothelial cells. The mechanism by which initiation occurs is uncertain. Zinc-dependent binding of plasma proteins to gC1qR, cytokeratin 1, and perhaps u-PAR is requisite for activation to take place. We demonstrate here that during a 2 hour incubation time plasma deficient in either factor XII or high molecular weight kininogen (HK) fails to activate, as compared to normal plasma, but with more prolonged incubation, factor XII-deficient plasma gradually activates while HK-deficient plasma does not. Our data support both factor XII-dependent (rapid) and factor XII-independent (slow) mechanisms; the latter may require a cell-derived protease to activate prekallikrein and the presence of zinc ions and HK.

Combinations of variations in multiple genes are associated with hypertension

The genetic analysis of hypertension has revealed complex and inconsistent results, making it difficult to draw clear conclusions regarding the impact of specific genes on blood pressure regulation in diverse human populations. Some of the confusion from previous studies is probably due to undetected gene-gene interactions. Instead of focusing on the effects of single genes on hypertension, we examined the effects of interactions of alleles at 4 candidate loci. Three of the loci are in the renin-angiotensin-system, angiotensinogen, ACE, and angiotensin II type 1 receptor, and they have been associated with hypertension in at least 1 previous study. The fourth locus studied is a previously undescribed locus, named FJ. In total, 7 polymorphic sites at these loci were analyzed for their association with hypertension in 51 normotensive and 126 hypertensive age-matched individuals. There were no significant differences between the 2 phenotypic classes with respect to either allele or genotype frequencies. However, when we tested for nonallelic associations (linkage disequilibrium), we found that of the 120 multilocus comparisons, 16 deviated significantly from random in the hypertensive class, but there were no significant deviations in the normotensive group. These findings suggest that genetic interactions between multiple loci rather than variants of a single gene underlie the genetic basis of hypertension in our study subjects. We hypothesize that such interactions may account for the inconsistent findings in previous studies because, unlike our study, prior studies almost always examined single-locus effects and did not consider the effects of variation at other potentially interacting loci.

The role of bone scintigraphy in patients with Erdheim-Chester disease

Erdheim-Chester disease (ECD) is a rare disorder that has been reported fewer than 60 times in the literature. Although clinical findings seem to be specific at first sight, histologic classification remains unclear. It has not been decided whether ECD is part of the spectrum of histiocytoses or whether it may be a lipid storage disorder or even a primary macrophage cell disorder, although it does show a distinct histologic pattern. However, the clinical appearance alone shows several typical features, rendering the diagnosis very probable if present. This article illustrates the importance of bone scanning in ECD, because the scintigraphic pattern of involved skeletal sites may in themselves lead to the diagnosis. Several differential diagnoses are considered. The importance of bone scintigraphy as an imaging method in patients with an unclear diagnosis is discussed, as exemplary in ECD, as is its role for the detection of sites of skeletal involvement in other diseases.

Accurate differentiation of parkinsonism and essential tremor using visual assessment of [123I]-FP-CIT SPECT imaging: the [123I]-FP-CIT study group

OBJECTIVE

To evaluate whether visual assessment of [123I]-FP-CIT (DaTSCAN, Nycomed Amersham, plc) single photon emission computerized tomography (SPECT) images can differentiate between parkinsonism and essential tremor (ET).

METHODS

[123I]-FP-CIT SPECT imaging was conducted in a six-center study of 158 patients with a clinical diagnosis of parkinsonism compared with 27 ET cases and 35 healthy volunteers. Striatal uptake of the radioligand was graded normal or abnormal, and abnormal images were further graded to three levels of severity. An institutional read whereby each center visually assessed the images blinded to the clinical data and a consensus blinded read by a panel of five was undertaken.

RESULTS

The institutional reading scored 154 of 158 cases of parkinsonism abnormal, all 27 cases of ET as normal, and 34 of 35 healthy volunteers as normal compared with the consensus blinded read scoring 150 cases of parkinsonism as abnormal, 25 ET cases as normal, and 33 healthy volunteers as normal. Sensitivity for the clinical diagnosis of parkinsonism was 97% and specificity for ET was 100% for the institutional read, whereas sensitivity was 95% and specificity 93% for the consensus blinded read. Semiquantitative analysis of specific: nonspecific caudate and putamen uptake were consistent with the results of visual inspection.

CONCLUSION

Visual assessment of [123I]-FP-CIT SPECT images is an easily applied diagnostic test which is helpful in the differential diagnosis of tremor disorders and in confirming a clinical diagnosis of a hypokinetic-rigid syndrome.

[Studies on significance of sentinel lymphadenectomy in pharyngeal and laryngeal carcinoma]

BACKGROUND

Management of the suspected N0-neck (sonography and CT) in squamous cell carcinoma (SCC) of the head and neck is discussed controversially. The question arises whether the sentinel node (SN) concept as it is performed in different areas of clinical oncology is applicable to ear, nose, and throat medicine.

METHODS

Nine male patients with SCC were studied (4 oropharynx, 2 hypopharynx, and 3 larynx) in whom different lymph node status was diagnosed clinically (5 x N0, 2 x N1, 2 x N2c). After intraoperative scintillation probe detection, the histological examination of the SN with neck dissection (ND) specimen followed.

RESULTS

In 7 of 9 cases SN detection was successful. In 4 of 5 cases of clinical N0 status, SN, and ND specimens were free of tumor histologically, while in one patient radiolabel-identified SN showed tumor cells in histological examination. In 2 patients with clinical N1 neck, SN, and ND were histologically tumor-free in one patient and contained one single tumor metastasis located in the SN in the other patient. In 2 patients with clinically and histologically proven N2c neck, lymph nodes located in regions II and III showed metastasis including capsular rupture. In both cases no lymph node radioactivity was detectable during the operation.

CONCLUSIONS

The results suggest that sentinel lymphonodectomy may be suited for ear, nose, and throat medicine. Before it is applied to clinical practice, further problems must be resolved. These include the short distance between the primary injection side and lymph nodes and the influence of intranodal tumor metastasis on the uptake of the radiolabeled tracer.