Waardenburg Syndrome Type I with Heterochromia Iridis and Circumscribed Hypopigmentation of the Skin

Abstract: We report a 3‐year‐old girl with autosomal dominant inherited Waardenburg syndrome type I showing circumscribed hypopigmentation of the skin, heterochromia iridis, sensorineural deafness, and dental aberrations. Clinical diagnosis was confirmed by the identification of an underlying missense mutation (C811T) in the PAX3 gene. Early diagnosis of Waardenburg syndrome among children with pigment anomalies enables a successful interdisciplinary medical care.     

HLA-DR3 in dermatitis herpetiformis

Twenty-one patients with dermatitis herpetiformis were typed for HLA-ABC and -DR determinants. The incidence of HLA-AI, -B8 and -DR3 antigens was found to be significantly higher (P: = 10^?3, <10^?6 and <10^?6, respectively) among patients with dermatitis herpetiformis than among the normal population. HLA-DR3 was found in 85.7% of patients, HLA-B8 in 66.7% and HLA-Ai in 61.9% only. These results indicate that HLA-DR3 is the antigen primarily associated in dermatitis herpetiformis and the latter antigens (HLA-Ai and -B8) are present in increased incidence, probably due to the known linkage disequilibrium of these antigens with HLA-DR3.     

Changes in AV Node Conduction Curves Following Slow Pathway Modification

GELLER, J.C., et al. : Changes in AV Node Conduction Curves Following Slow Pathway Modification. Dual AV node physiology often persists after successful slow pathway (SP) ablation, and the mechanism of tachycardia elimination is unresolved. Therefore, AV node conduction curves were analyzed following successful ablation (  4 ± 1  energy applications) in 85 consecutive patients (58 women, age  50 ± 2  years) with typical AVNRT. Twenty-seven patients (32%) had complete elimination (group 1) whereas 58 (68%) patients had persistence (group 2) of dual AV node physiology. A significant increase in the AV node Wenckebach cycle length (WB-CL) was observed in both groups (  310 ± 9 to 351 ± 15 ms  in group 1, and  325 ± 8 to 369 ± 9 ms  in group  2, P < 0.05  ). A decrease in the fast pathway (FP) ERP (  339 ± 15 to 279 ± 12 ms  ) and an increase in the maximum FP AH interval (  141 ± 5 to 171 ± 7  ) were observed only in group 1 (P < 0.05). In group 2, no change in the SP ERP (  267 ± 7 to 280 ± 10 ms  ) was observed, and the change in the maximum SP-AH following ablation showed a significant inverse relation to the maximum SP-AH at baseline in group 2. In conclusion, (1) an increase in the WB-CL is observed independent of the persistence or elimination of dual physiology after successful ablation; (2) when dual physiology is eliminated, significant changes in the FP ERP and the maximum FP-AH occur; (3) when dual physiology persists, FP physiology and the SP ERP remain unchanged, and a significant inverse relation between the change in the maximum SP-AH following ablation and the maximum baseline SP-AH is observed.     

Neonatal rat cartilage has the capacity for tissue regeneration

One of the most relevant issues in future medicine is tissue regeneration. Transplantation medicine alone cannot solve the problem of incurable conditions of vital organs. One approach to this might be the replication of the spontaneous regeneration that is found in embryonic/neonatal tissue. In this study, a tissue model for basic investigation of regeneration mechanisms in vivo was established. We demonstrated by histology and immunohistochemical staining for types I and II collagen that neonatal rat cartilage unlike adult cartilage has the capacity for rapid scarfree regeneration after full-thickness incision. The underlying mechanism was identified in the preserved proliferative capacity of neonatal chondrocytes. This in vivo model should prove useful in further studies of the role of cellular (e.g., GA cell cycle regulators) and extracellular (e.g., cytokines) factors in tissue regeneration and wound healing.     

Plasmodium falciparum malaria blood stage parasites preferentially inhibit macrophages with high phagocytic activity

Exposure to malaria blood stage antigens results in several defects of macrophages/monocytes one of which is an irreversible reduction of phagocytic activity. In the present study we analysed phagocytic activity of subpopulations of human monocyte-derived-macrophages (MDM) based on the capacity of individual cells to ingest FITC-labelled microbeads. The results demonstrate that malaria infection affected predominantly MDM subpopulations with high level of phagocytosis. This population decreased during parasitaemia, however, during recovery from the infection the highly phagocytic cells replaced the damaged cells. The exposure of MDM cultures to blood stage antigens showed that the highly active macrophages from persons with active malaria infection decreased further, while the population increased during recovery. Furthermore, we observed that while ingestion of a few parasitized RBC (3 schizonts) stimulated phagocytosis, larger amounts or longer exposure periods eventually paralysed the entire phagocytic system. Accordingly, by selectively blocking actively phagocytizing macrophages, the malaria parasite prevents both specific and non-specific immune responses, which are initiated by macrophages as phagocytes and professional antigen presenting cells.     

THE EFFECT OF D- VERSUS L- PROPRANOLOL IN THE TREATMENT OF HYPERTHYROIDISM

The purpose of this study is to determine whether there is a difference in treatment of hyperthyroidism using either the D- or L-isomer of propranolol. Two groups of 20 patients with overt hyperthyroidism received either 120 mg L- or D-propranolol each for a period of 5 days. In the D-propranolol administered group there was a significant decrease in TT3 and fT3 plasma levels and in the ratio of TT3 to TT4; however, a significant increase occurred in rT3 values up to day 5. On the other hand, L-propranolol treatment resulted in a less pronounced decrease in TT4 and TT3 values, while all other thyroid hormone levels remained unchanged as, above all, did the T3/T4 ratio. The well known effect of D,L-propranolol upon peripheral conversion of T4 to T3 is thus not due to the beta-blocking action of L-propranolol but is mainly conditioned by the D-isomer which has no beta-blocking action itself.     

District health systems: users' preferences for services in Benin

The function of district health systems in Benin Republic wascritically assessed, and special consideration was given tothe acceptability of available health services from the users'point of view. Using a representative household survey, servicerecords, a survey amongst service users, participant observationand qualitative interviews, we obtained data on the use of differentservices offered by the modern public health system, as wellas on reasons for non-use and preference for treatment by traditionalpractitioners or within the family. Although in the last 15 years accessibility to health serviceshas improved remarkably, services are not fully accepted. Under-utilizationof services seems to be due to their low quality, and users'reluctance to consult them. Users are faced with prohibitivecosts, and staff attitudes have further decreased confidence.A major reason for this seems to be staff incompetence in counsellingpatients and clients. Health systems research studies focusing on the clients' viewsmay provoke a critical reflection of everyday practices, providea review of the objectives of district health systems, and leadto discussions on how to improve the performance and qualityof district health teams. This paper gives an account of thepositive experience with participatory workshops at differentlevels of the health system, which constitute a way of ensuringthat study results will be discussed and used at district andnational level.     

Percutaneous Pacemaker Lead-Transsecting Catheter

We describe the development and successful use of a percutaneous lead-transsection catheter. It was used in two patients in whom removal of chronically implanted atrial pacing leads could not be accomplished by traction.