Persistence of Mammary Artery Branches and Blood Supply to the Left Anterior Descending Artery

Background. Partial harvesting of the left internal mammary artery (LIMA) is a widespread technique used during minimally invasive coronary operations performed through a left anterior small thoracotomy. The influence of persisting LIMA branches was investigated to evaluate their effect on the blood flow of the left anterior descending artery.

Methods. Thirty patients, 15 with totally (group A) and 15 with partially (group B) harvested LIMAs, were evaluated. All the patients underwent postoperative angiography, during which a flow map of the LIMA was performed. The average peak velocity and the diastolic-to-systolic peak velocity ratio were recorded. The LIMA graft flow pattern was recorded in the proximal and distal thirds of the artery. Intramammary adenosine (12 to 14 μg) was injected and the average peak velocities before and after injection were calculated.

Results. The average peak velocity was similar in both groups in the proximal and distal thirds of the LIMA (25 ± 7 and 26 ± 5 cm/sec, respectively, in group A versus 27 ± 5 and 25 ± 5 cm/sec, respectively in group B; p = NS). The diastolic-to-systolic peak velocity ratio was similar proximally (0.78 ± 0.3 in group A versus 0.69 ± 0.3 cm/s in group B; p = NS), but not distally (1.72 ± 0.1 in group A versus 0.97 ± 0.3 in group B; p < 0.0005). The LIMA graft flow reserve was similar both proximally and distally (2.6 ± 0.6 and 2.5 ± 0.3 cm/s, respectively, in group A versus 2.6 ± 0.5 and 2.6 ± 0.3 cm/s, respectively, in group B; p = NS).

Conclusions. The persistence of LIMA branches does not influence the blood flow of the left anterior descending artery after acute adenosine-induced myocardial hyperemia. If a left anterior small thoracotomy is used in left anterior descending artery direct revascularization, complete LIMA harvesting is not mandatory and depends on the personal preference of the surgeon.     

Association of human polyomavirus JC with peripheral blood of immunoimpaired and healthy individuals

JC virus (JCV) infection is regularly asymptomatic in healthy individuals. In contrast, in immunocompromised individuals, highly activated virus replication may lead to PML. Peripheral blood cells (PBCs) are found to habor JCV DNA in healthy and diseased individuals and it is discussed that they might be responsible for dissemination of the virus to the central nervous system (CNS) during persistence. To better understand the role of JCV DNA in PBCs for persistent infection and pathogenesis, the authors characterized the extent of JCV infection in Ficoll-gradient purified blood cells (peripheral blood mononuclear cells [PBMCs]) of healthy and human immunodeficiency virus type 1 (HIV-1)-infected individuals. Virus activation in PBMCs from healthy JCV-infected individuals was found at a rate of 0% to 38% at low polymerase chain reaction (PCR) sensitivity. In progressive multifocal leukoencephalopathy (PML) patients, a stronger signal was found, indicating increased virus activation. JCV DNA was regularly detected in T and B lymphocytes and in monocytes at low levels. However, granulocytes were shown to be the predominant reservoir of JCV DNA harboring high copy numbers. Although the overall distribution of viral genomes holds true for the population studied, in the individual, a markedly changed pattern of distribution can be found.     

Central effects of systemic lidocaine mediated by glycine spinal receptors: an iontophoretic study in the rat spinal cord

The objective of this investigation was to demonstrate the possible interactions of systemic lidocaine (lido) with inhibitory receptors in the spinal cord. In the lumbar dorsal horn of anesthetized and curarized rats, 60 physiologically identified, wide dynamic range (WDR) neurons, were recorded extracellularly. Glutamate, glycine and its selective antagonist, strychnine, were iontophoretically applied onto the neurons either singularly or concurrently. The effects of systemic lido on the drug-induced frequency changes and the interaction with the glycine receptors, using strychnine as a probe, were studied. It was consistently found that (i) lido (3–4 mg/kg) inhibited the excitatory responses to iontophoretic glutamate, (ii) this inhibition was significantly antagonized by concurrent iontophoretic strychnine, (iii) iontophoretic glycine induced comparable glutamate inhibition that was reversed by strychnine. In contrast, no effect on glutamate-induced excitations was observed when lido was applied by micropressure or a different local anesthetic was systemically administered. The results suggest that central inhibitory effects of lido could by mediated by spinal strychnine-sensitive glycine receptors, activated by lido itself or possibly by its glycine residue-bearing metabolites.     

Motor neuron disease and optic neuropathy after acute exposure to a methanol-containing solvent mixture.

A 34-years-old floor-layer developed optic neuropathy and motor neuron disease after being accidentally exposed to a solvent mixture containing methanol and other substances. Optic neuropathy is a complication of methanol poisoning, but the onset of a motor neuron disorder resembling amyotrophic lateral sclerosis after the exposure to these substances has not been previously described. The temporal onset of the clinical symptoms, biological plausibility, young age of the patient and absence of neurological disorders in the family history raises suspicion of a possible causative relationship.     

Failed Amplatzer Septal Occluder device implantation due to an embryonic septal remnant

Embryonic remnants of incomplete septation may complicate occlusiondevice implantation in secundum atrial septal defects (sASD)even if stiff devices such as the Amplatzer Occluder are used. A 35-year-old woman was referred to our center for evaluationof a sASD.     

Retinal degeneration associated with RDH12 mutations results from decreased 11-cis retinal synthesis due to disruption of the visual cycle

Human Molecular Genetics     

Release of vasopressin from supraoptic neurons within the median eminence in vivo. A combined microdialysis and push-pull perfusion study in the rat

The present study was designed to investigate whether or not arginine vasopressin (AVP) is released from magnocellular neurons within the median eminence (ME) in vivo. Urethane-anesthetized adult male Wistar rats were equipped with a microdialysis probe aimed at the supraoptic (SON) or paraventricular nucleus (PVN), a push-pull perfusion probe resting in the ME, and a blood microdialysis probe within the jugular vein. Dialysis of the SON (but not the PVN) with Ringer's solution containing 56 mmol l⁻¹ K⁺ resulted in an increase in AVP release within the ME (to 492 ± 192% of release during basal conditions,P < 0.05) and into blood (to 138 ± 9%,P < 0.01) whereby the release probably occurred from axonal swellings and nerve terminals of supraoptic neurons which project through the internal zone of the ME to the posterior pituitary. The calculated amount of AVP released into the extracellular fluid of the ME was high enough (approximately 1 pg/μ1) to hypothesize that the neuropeptide could enter the portal blood capillaries in physiologically relevant concentrations. Taken together, the present study indicates that activation of magnocellular neurons is accompanied by release of AVP within the median eminence. We assume that AVP released in this way might mediate a communication between the hypothalamic-neurohypophysial system and the hypothalamic-pituitary-adrenal axis in response to selected stressful stimuli.