Bacteriological diagnosis of Neisseria ovis. Apropos of a strain isolated from keratoconjunctivitis of lambs

The authors report a case of bacteriologic diagnosis of Neisseria ovis isolated from a keratoconjunctivitis of lamb. Difficulties of diagnosis and taxonomic position of N. ovis are briefly discussed.     

Dual-color imaging of nuclear-cytoplasmic dynamics, viability, and proliferation of cancer cells in the portal vein area

We used dual-color in vivo cellular imaging to visualize trafficking, nuclear-cytoplasmic dynamics, and the viability of cancer cells after their injection into the portal vein of mice. For these studies, we used dual-color fluorescent cancer cells that express green fluorescent protein (GFP) linked to histone H2B in the nucleus and retroviral red fluorescent protein (RFP) in the cytoplasm. Human HCT-116-GFP-RFP colon cancer and mouse mammary tumor (MMT) cells were HCT-116-GFP-RFP in the portal vein of nude mice. The cells were observed intravitally in the liver at the single-cell level using the Olympus OV100 whole-mouse imaging system. Most HCT-116-GFP-RFP cells remained in sinusoids near peripheral portal veins. Only a small fraction of the cancer cells invaded the lobular area. Extensive clasmocytosis (destruction of the cytoplasm) of the HCT-116-GFP-RFP cells occurred within 6 hours. The number of apoptotic cells rapidly increased within the portal vein within 12 hours of injection. Apoptosis was readily visualized in the dual-color cells by their altered nuclear morphology. The data suggest rapid death of HCT-116-GFP-RFP cells in the portal vein. In contrast, dual-color MMT-GFP-RFP cells injected into the portal vein mostly survived in the liver of nude mice 24 hours after injection. Many surviving MMT-GFP-RFP cells showed invasive figures with cytoplasmic protrusions. The cells grew aggressively and formed colonies in the liver. However, when the host mice were pretreated with cyclophosphamide, the HCT-116-GFP-RFP cells also survived and formed colonies in the liver after portal vein injection. These results suggest that a cyclophosphamide-sensitive host cellular system attacked the HCT-116-GFP-RFP cells but could not effectively kill the MMT-GFP-RFP cells.     

In vivo color-coded imaging of the interaction of colon cancer cells and splenocytes in the formation of liver metastases

The role of host cells in tumor progression and metastasis is critical. Intrasplenic injection of tumor cells has long been known as an effective method of developing liver metastases in nude mice, whereas portal vein (PV) injection of tumor cells can result in rapid death of the tumor cells. Host cells were thought to play a role in these phenomena. We report here that after splenic injection of tumor cells, splenocytes cotraffic with the tumor cells to the liver and facilitate metastatic colony formation. Human colon cancer cells that express green fluorescent protein (GFP) linked to histone H2B in the nucleus and red fluorescent protein (RFP) in the cytoplasm (HCT-116-GFP-RFP) were injected in either the PV or spleen of nude mice and imaged at the subcellular level in vivo. Extensive clasmocytosis (destruction of the cytoplasm) of the cancer cells occurred within 6 hours after PV injection and essentially all the cancer cells died. In contrast, splenic injection of these tumor cells resulted in the aggressive formation of liver and distant metastasis. GFP spleen cells were found in the liver metastases that resulted from intrasplenic injection of the tumor cells in transgenic nude mice ubiquitously expressing GFP. When GFP spleen cells and the RFP cancer cells were coinjected in the PV, liver metastasis resulted that contained GFP spleen cells. These results suggest a novel tumor-host interaction that enables efficient formation of liver metastasis via intrasplenic injection.     

Risk of needlestick injuries by injection pens

Injection pens are used by patients when auto-administering medication (insulin, interferon, apokinon etc.) by the subcutaneous route. The objective of this study was to evaluate the rate of injection pen use by healthcare workers (HCWs) and the associated risk of needlestick injuries to document and compare injury rates between injection pens and subcutaneous syringes. A one-year retrospective study was conducted in 24 sentinel French public hospitals. All needlestick injuries linked to subcutaneous injection procedures, which were voluntarily reported to occupational medicine departments by HCWs between October 1999 and September 2000, were documented using a standardized questionnaire. Additional data (total number of needlestick injuries reported, number of subcutaneous injection devices purchased) were collected over the same period. A total of 144 needlestick injuries associated with subcutaneous injection were reported. The needlestick injury rate for injection pens was six times the rate for disposable syringes. Needlestick injuries with injection pens accounted for 39% of needlestick injuries linked with subcutaneous injection. In all, 60% of needlestick injuries with injection pens were related to disassembly. Injection pens are associated with needlestick injuries six times more often than syringes. Nevertheless, injection pens have been shown to improve the quality of treatment for patients and may improve treatment observance. This study points to the need for safety-engineered injection pens.     

Pitfalls in the symptomatology of orthodontics

Certain anatomical characteristics typical of infancy may be the cause of problems during clinical examinations in orthodontics. The rounded cheeks of our small patients often mask the presence of a cephalic dysymmetry . Furthermore, the particular relation between the gums and the dental crowns makes it more difficult for evaluation of the vestibulo-lingual and mesio-distal inclinations of the teeth and the interpretation of the articulation. However, most pitfalls arise during examination of the buccal musculature at rest and during activity. These errors in infants can be avoided by the use of simple precautions.