Platelet-derived growth factor concentrations in platelet-poor plasma and urine from patients with myeloproliferative disorders

Our enzyme-linked immunosorbent assay (ELISA) for measuring human platelet-derived growth factor (PDGF) detects nanogram quantities (ranging from 0.007 to 16 ng/100 microL) in purified PDGF standards. This assay is sensitive enough for studying plasma and urine. The range in normal volunteers was 0.6 to 2.3 micrograms/L for platelet-poor plasma and 1.4 to 3.3 micrograms/L for urine. We determined PDGF levels in the circulation (outside platelets) in patients with myeloproliferative diseases. Platelet-poor plasma and urine PDGF were significantly elevated in patients with myelofibrosis (6.2 +/- 2.0 micrograms/L for plasma; 7.8 +/- 2.4 micrograms/L for urine) and essential thrombocythemia (5.5 +/- 1.5 micrograms/L for plasma; 11.4 +/- 2.2 micrograms/L for urine), but not in patients with chronic myelogenous leukemia (2.1 +/- 0.4 micrograms/L for plasma; 2.8 +/- 1.2 micrograms/L for urine). Polycythemia vera produced an intermediate pattern: although plasma PDGF was within the normal range (2.1 +/- 0.2 micrograms/L), urine levels were increased (3.7 +/- 0.6 micrograms/L). These results show that PDGF is increased in the circulation in some but not all myeloproliferative diseases, and suggest that this is due to abnormal in vivo release from either megakaryocytes in the bone marrow or circulating platelets.     

Human platelet cytoskeletons: specific content of glycolipids and phospholipids

The lipid composition of platelet cytoskeletons was analyzed. Triton X- 100 (0.5%) was used to prepare cytoskeletons from thrombin-treated platelets. The lipid/protein ratio of platelet cytoskeletons was 0.260 and the phospholipid/protein ratio was 0.177, which were comparable to the ratios present in platelets. However, there was a selective enrichment of platelet lipids in platelet cytoskeletons. Only 2 of the 5 major platelet phospholipids were detected. About 14% platelet sphingomyelin and 2% platelet phosphatidylcholine were present in platelet cytoskeletons. Only 1 of the 4 platelet neutral glycolipids, trihexosyl ceramide, was detected and was about 7% of that in intact platelets. Two percent of platelet hematoside, the predominant ganglioside in platelets, was found in cytoskeletons. Six percent of platelet cholesterol was present in platelet cytoskeletons, while no other neutral lipid could be detected. The study demonstrates that the lipid/protein ratio of platelet cytoskeletons is similar to that in platelets, but the composition of cytoskeleton lipids is specific and distinctly different from that in platelets. The selective glycolipid and phospholipid composition of cytoskeletons may be important for cytoskeleton and platelet function.     

Immunolocalization of inducible nitric oxide synthase in synovium and cartilage in rheumatoid arthritis and osteoarthritis

Nitric oxide has been implicated as a mediator of inflammatory arthritis, and recent work has shown that pro-inflammatory cytokines stimulate NO production in vitro by activation of the inducible nitric oxide synthase (iNOS) pathway. In order to identify the cellular sources of NO production within the joint, we have used immunohistochemical techniques to study the distribution of iNOS in synovium and cartilage from normal and diseased joints. iNOS was most strongly expressed in the synovial lining layer, subsynovium, vascular smooth muscle and chondrocytes from patients with rheumatoid arthritis (RA). Analysis of serial sections, coupled with double immunofluorescent staining, showed that the CD68+ macrophages in the synovial lining layer and, to a lesser extent, fibroblasts were the predominant source of iNOS within synovium, whereas T cells, B cells and neutrophils were negative. A similar pattern of iNOS staining was seen in osteoarthritis, but fewer cells were iNOS positive and the intensity of staining, particularly in cartilage, was much weaker than in RA. In contrast, no evidence of iNOS was detected in non- inflammatory synovium or in cartilage derived from normal joints (fractured neck of femur). In conclusion, these data support the hypothesis that synovium and cartilage are important sources of increased NO production in patients with inflammatory arthritis. Localization of iNOS at these sites within the inflamed joint raises the possibility that increased local production of NO may contribute to the pathogenesis of inflammatory arthritis by increasing synovial blood flow and by modulating cellular function within synovium and articular cartilage.      

Fractures in the maxillofacial region: A four year retrospective study

Introduction: The incidence of maxillofacial injuries is on the rise due to motor vehicle accidents and increased incidence of violence in recent times. The aim of this retrospective study was to determine the incidence, aetiology, the pattern of fractures, their management with open reduction and internal fixation (ORIF) and complications, if any.     

Cation exchange high performance liquid chromatography for diagnosis of haemoglobinopathies

Background: Cation exchange high performance liquid chromatography (HPLC) is emerging as the method of choice for initial screening and diagnosis of haemoglobinopathies. The use of alkaline and acid gel electrophoresis in the developing countries may result in incorrect diagnosis of haemoglobinopathies. The aim of the study is to assess the accuracy and precision of diagnosis of haemoglobinopathies by HPLC and its possible advantage over conventional techniques.     

Management of Zygomatic Complex Fracture in Armed Forces

Introduction

The Armed Forces personnel are exposed to various kinds of injuries due to the nature of their duties. Increase in motorized population without taking protective measures and rise in violence has contributed towards maxillofacial injuries. The aim of this study was to determine the incidence, aetiology and management of injuries resulting in fracture of the Zygomatic complex in Armed Forces personnel and their families.

Methods

This study was conducted at Command Military Dental Centre (EC). Out of 90 maxillofacial injuries, 40 individuals (44.4%) were treated for Zygomatic complex fractures, majority were in their third decade of life and RTA was the leading cause.

Result

Thirty seven individuals (92.5%) recovered uneventfully, while three (7.5%) patients had post operative complications such as enophthalmos, paraesthesia, diplopia, facial asymmetry, palpability of implants and facial nerve paresis. These complications were subsequently treated successfully.

Conclusion

The midface is composed of fragile bones which get fractured easily. It is imperative to educate people regarding the use of protective headgears/seat belts while travelling in motorized transport.Key Words: Zygomatic complex, Road traffic accident (RTA)     

The NO donor DETA-NONOate reversibly activates an inward current in neurones and is not mediated by the released nitric oxide

Background and purpose:

It has been previously shown that high levels of nitric oxide (NO), from NO donors, kill neurones, but the mechanisms are unclear.

Experimental approach:

The effects of NO donors on the electrical properties of rat cultured cerebellar granule cells (CGC neurones) were investigated using the whole-cell patch-clamp technique.

Key results:

The NO donor (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NONOate or NOC-18) caused a rapid, persistent, but fully reversible inward current that was associated with an increase in baseline noise and was concentration dependent (100 µM–10 mM). The response to 3 mM DETA-NONOate was completely inhibited by 1 mM gadolinium, but not by NO scavengers (1 mM haemoglobin or 1 mM PTIO) or glutamate receptor antagonists (10 µM MK-801 or 60 µM CNQX). Application of decomposed 3 mM DETA-NONOate or 3 mM nitrite had no effect. In contrast, the NO donor S-nitrosoglutathione (GSNO) caused a rapid, persistent, but fully reversible outward current that was also concentration dependent (1–10 mM). The 3 mM GSNO response was unaltered by NO scavengers, glutamate antagonists or gadolinium, but was mimicked by decomposed 3 mM GSNO and 3 mM oxidized glutathione.

Conclusions and implications:

These results suggest that DETA-NONOate directly activates cation-selective channels, causing an inward current in CGCs. In contrast, GSNO causes an outward current in these cells. Some of the effects of these NO donors are independent of NO, and thus caution is required in interpreting results when using high concentrations of these compounds.     

One-stage Fowler-Stephens orchidopexy for impalpable undescended testis

Background The Fowler-Stephens orchidopexy (FSO) is a well-described treatment for high maldescended testes where the limiting factor for successful placement in the scrotum is short testicular vessels. The operation involves division of these vessels. The testicular blood supply is then dependent on collaterals from the vasal artery. Aims To assess the long-term outcome of patients who underwent this procedure in our institution. Methods The medical records of 20 patients who underwent 22 FSO from 1978 to 1999 by one urologist (HB) were reviewed. Outcome was assessed in terms of testicular position and size. Results Age at operation ranged from 2 to 14 years (mean 5.8 years). All patients had a one-stage FSO and in two of them the procedure was bilateral. In five patients, FSO was preceded by a diagnostic laparoscopy. Mean follow up was 22 months (range 0–121 months). Overall, results were considered good in 18 of 22 testes (82%). Conclusion Our results for the one-stage FSO are comparable with other procedures for the management of high maldescended testis.