Laparoscopic infrared imaging

A system was developed to determine the potential role of infrared imaging as a tool for localizing anatomic structures and assessing tissue viability during laparoscopic surgical procedures. A camera system sensitive to emitted energy in the midinfrared range (3-5 micron) was incorporated into a two-channel visible laparoscope. Laparoscopic cholecystectomy, dissection of the ureter, and assessment of bowel perfusion were performed in a porcine model with the aid of this infrared imaging system. Inexperienced laparoscopists were asked to localize and differentiate structures before dissection using the visible system and then using the infrared system. Assessment of bowel perfusion was also conducted using each system. Infrared imaging proved to be useful in differentiating between blood vessels and other anatomic structures. Differentiation of the cystic duct and arteries and transperitoneal localization of the ureter were successful in all instances using the infrared system when use of the visible system had failed. This system also permitted assessment of bowel perfusion during laparoscopic occlusion of mesenteric vessels. These initial studies demonstrate that infrared imaging may improve the differentiation and localization of anatomic structures and allow assessment of physiologic parameters such as perfusion not previously attainable with visible laparoscopic techniques. It may thus potentially be a powerful adjunct to laparoscopic surgery.     

Activation of microtubule-associated protein kinase (Erk) and p70 S6 kinase by D2 dopamine receptors

The ability of human and rat D2(short) and D2(long) dopamine receptors to activate microtubule-associated protein (MAP) kinase (Erk1/2) and p70 S6 kinase has been investigated in recombinant cells expressing these receptors. In cells expressing the D2(short) receptor, dopamine activated both enzymes in a transient manner but with very different time courses, with activation of Erk being much quicker. Activation of both enzymes by dopamine was dose-dependent and could be prevented by a range of selective dopamine antagonists. Excellent correlations were observed between the potencies of the antagonists for blocking enzyme activation and their affinities for the D2 dopamine receptor. Activation of Erk and of p70 S6 kinase via the D2 dopamine receptors was prevented by pretreatment of the cells with pertussis toxin, indicating the involvement of G proteins of the Gi or Go family. Inhibitors of phosphatidylinositol 3-kinase (PI 3-kinase) were found to block substantially, but not completely, activation of p70 S6 kinase by dopamine, suggesting the involvement of PI 3-kinase-dependent and -independent signalling pathways in its control by dopamine. p70 S6 kinase activation was completely blocked by rapamycin. In the case of Erk, activation was partially blocked by wortmannin or LY294002, indicating a possible link with PI 3-kinase.     

Technique of lateral canthoplasty for the correction of macropalpebral fissure in the dog

Chiari III malformations are extremely rare hindbrain malformations that are associated with a high early mortality rate, or severe neurologic deficits in the survivors. The preferred treatment is early operative closure and CSF shunting. We report a case of a newborn infant with a Chiari III malformation with displacement of the brainstem and cerebellum into the cervical encephalocele which precluded immediate operative closure of the defect. Instead, a ventriculoperitoneal shunt was placed and the patient was followed with serial imaging studies. The child survived. The shunt allowed the brainstem and cerebellum to regress into the cervical spinal canal as the dilated cerebral aqueduct and fourth ventricle decompressed. A delayed closure of the cervical encephalocele was performed at 30 months of age. Cerebrospinal fluid diversion with delayed closure may be an option for large lesions.     

Budd-Chiari syndrome following repair of a giant omphalocele

We report a case of Budd-Chiari syndrome following repair of a giant omphalocele. Thrombosis of hepatic veins and of retrohepatic inferior vena cava may result from direct pressure on the hepatic venous outlet after visceral reduction and final abdominal wall closure.     

Tumour-proliferative fraction and growth factor expression as markers of tumour response to radiotherapy in cancer of the uterine cervix

This study seeks to define the role of pretreatment of evaluation of tumour growth fraction in cervical cancer and its relationship to the clinical course of the disease. In addition, it also seeks to explain whether cell kinetics and growth factor expression have an association with tumour response to radiotherapy and hence could be of value in the management of patients. All pre-treatment biopsies were analysed for the tumour-proliferative compartment by evaluation of Ki67 antigen expression and argyrophilic nucleolar organiser region (AgNOR) counts. Growth factor analysis was done by analysing for expression of epidermal growth factor (EGF), epidermal growth factor receptor (EGF-R) and transforming growth factors alpha and beta (TGFalpha, TGFbeta). A total of 152 patients were evaluated and a correlation obtained between pre-treatment status of the tumour-growth-fraction-associated markers and clinical outcome following radiotherapy. Such patients were either disease-free (group 1, n=106) or with residual/recurrent disease (group 2, n=46) at a 16-month follow-up. Pre-treatment analysis of AgNOR significantly correlated to disease status after treatment (r=-0.517, P=0.0000). This may be due to an effect of cell proliferation. Lower AgNOR counts were significantly associated with recurrent/residual tumours, suggesting that increased proliferative activity may be a positive prognostic indicator. Similar results were also obtained for the other proliferation-associated marker Ki67 (r=-0.443, P=0.0000). Expression of EGF and EGF-R also showed significant pre-treatment correlations with the final disease outcome (r=0.248, P=0.031 and r=0.503, P=0.0000 respectively). Both these markers were expressed more by patients belonging to group 2. The opposite was the case for TGFalpha, where patients belonging to group 1 showed higher values (r=0.417, P=0.0001). The other growth factor investigated, TGFbeta, also showed a conspicuous differential expression in the two groups of patients (r=-0.604, P=0.0000). Group 1 patients showed mostly mild to moderate expression while most group 2 patients were negative for the growth factor. It therefore appears that tumours with high AgNOR counts and Ki67 index, along with expression of the two types of transforming growth factor (alpha and beta), responded better to radiotherapy.     

CTLA-4 promoter variants in patients with Graves'' disease and Hashimoto''s thyroiditis

A coronary artery dissection is a rare but well-known lethal complication associated with coronary perfusion. We herein report the case of a right coronary dissection that occurred after an aortic valve replacement. Coronary bypass grafting was successful after the establishment of mechanical biventricular support with an intra-aortic balloon pump and a right ventricular assist device.     

Annexin I is a local mediator in neural-endocrine feedback control of inflammation

From the electric signals measured after photoexcitation, the electrogenicity of the photocycle intermediates of bacteriorhodopsin were determined in a pH range of 4.5-9. Current measurements and absorption kinetic signals at five wavelengths were recorded in the time interval from 300 ns to 0.5 s. To fit the data, the model containing sequential intermediates connected by reversible first-order reactions was used. The electrogenicities were calculated from the integral of the current signal, by using the time-dependent concentrations of the intermediates, obtained from the fits. Almost all of the calculated electrogenicities were pH independent, suggesting that the charge motions occur inside the protein. Only the N intermediate exhibited pH-dependent electrogenicity, implying that the protonation of Asp96, from the intracellular part of the protein, is not from a well-determined proton donor. The calculated electrogenicities gave good approximations of all of the details of the measured electric signals.     

O-(fluoresceinylmethyl)hydroxylamine (OFMHA): a fluorescent reagent for detection of damaged nucleic acids

5- and 6-O-(Fluoresceinylmethyl)hydroxylamine (OFMHA, 5a, b) were prepared from the corresponding bis-pivaloyl-protected hydroxymethylfluoresceins (1a, b) in 50-70% yield. The hydroxylamine derivatives reacted smoothly with the abasic sites present in acid/heat stressed calf thymus DNA.     

Infectivity of African cassava mosaic virus clones to cassava by biolistic inoculation

Clones of an African cassava mosaic virus isolate originating from Nigeria (ACMV-NOg) were shown to be infectious to cassava by biolistic inoculation. The production of pseudorecombinants between ACMV-NOg and clones of an ACMV isolate originating from Kenya (ACMV-K) indicated that the lack of infectivity of ACMV-K to cassava was due to defect(s) in the DNA B genomic component; this component encodes two proteins involved in cell-to-cell movement. This is the first demonstration of infectivity of a cloned geminivirus to cassava and conclusively proves that ACMV is the causative agent of cassava mosaic disease. The potential uses of infectious ACMV clones and the means by which to introduce them into cassava are discussed.