Concettina Gillies

CONGENITAL ALVEOLAR CAPILLARY DYSPLASIA: A Developmental Vascular Anomaly Causing Persistent Pulmonary Hypertension of the Newborn

The clinical course and histologic findings are presented of an infant with an unusual form of pulmonary dysplasia. Characteristic sonographic findings and progressive hypoxemia led to the diagnosis of persistence of the fetal circulation. The patient expired despite ventilatory and pharmacologic intervention. Postmortem findings of severe pulmonary capillary hypoplasia, despite normal anatomical and biochemical parenchymal maturation, were observed. It is suggested that factors controlling pulmonary capillary maturation may be significantly different from those involved in airway and pulmonary parenchymal development.

Urinary Neutrophil Chemotactic Factors in Interstitial Cystitis Patients and a Rabbit Model of Bladder Inflammation

The present study investigates a possible source of inflammatory mediators involved in the pathogenesis of bladder inflammation characteristics of interstitial cystitis disease. Our tested hypothesis is that in response to injury, tissues of the urinary bladder participate in the initiation of bladder inflammation by releasing inflammatory mediators such as neutrophil chemotactic factors. Bladders of anesthetized rabbits (n = 7) were instilled with an acidic solution (pH 4.5) for 15 minutes, then washed with saline and instilled with sterile phosphate buffered saline (PBS) (pH 7.2) for an additional 45 minutes prior to sacrificing the rabbits. Control rabbits (n = 7) were instilled with sterile PBS (pH 7.2) for 15 minutes, then 45 minutes. The levels of neutrophil chemotactic factors were measured using modified Boyden chambers and rabbit peritoneal neutrophils as indicator cells. Results indicated the release of high levels of neutrophil chemotactic factors (via a checkerboard analysis) from acid-treated bladders after 15 minutes (70 +/- 4% of standard) and 45 minutes (80 +/- 7%). Electron microscopy analysis of these acid-treated bladders revealed the infiltration of a large number of neutrophils, which correlates with the recovery of neutrophil chemotactic factors. Control rabbits, on the other hand, showed low levels of chemotactic activity (less than 10 percent) and exhibited normal bladder morphology with absence of neutrophils. The glycosaminoglycan (GAG) layer was intact in both acid-treated and control bladders. High levels of neutrophil chemotactic factors were also detected in urine samples from eleven patients with interstitial cystitis (113 +/- 25%) (not due to interleukin-1 or leukotriene B4) which were not detected in urine samples from healthy volunteers (n = 9) or from thirteen control patients with bladder diseases other than interstitial cystitis. These preliminary studies indicate the capability of injured bladder tissues to release neutrophil chemotactic factors which contribute to the initiation of bladder inflammation. The presence of neutrophil chemotactic factors in urine samples of interstitial cystitis patients suggests a possible role of these mediators in the pathogenesis of the disease.

Functional and morphologic evidence of the presence of tissue-plasminogen activator in vascular nerves: Implications for a neurologic control of vessel wall fibrinolysis and rigidity†

Tissue plasminogen activator (t‐PA) is expressed by hypothalamic and peripheral sympathetic neurons. The sympathetic axons that permeate artery walls have not been investigated as possible sources of intramural t‐PA. The plasmin produced by such a system would locally activate both fibrinolysis and matrix metalloproteinases that regulate arterial collagen turnover. To assess this neural t‐PA production, we investigated the capacity of rat cervical sympathetic ganglion neurons to synthesize and release t‐PA, and the expression of the enzyme in carotid artery and the iris‐choroid microvascular tissues that receive the ganglion axon distribution. Functional studies confirmed that (i) the ganglion neuron cell bodies synthesize t‐PA mRNA, (ii) cultured ganglion carotid artery and iris‐choroid microvascular explants predominantly release t‐PA rather than urokinase, (iii) microvascular tissues release ∼20 times more t‐PA per milligram than carotid explants (which accords with the higher innervation density of small vessels), and (iv) removal of the endothelium did not cause major reductions in the t‐PA release from carotid and microvascular explants. Immunolocalization studies then confirmed a strong expression of the enzyme within the ganglion axons, the carotid adventitia that receives these axons, and the predominantly sympathetic axon terminals in the iris‐choroid microvasculature. These data indicate the existence of a previously undescribed system for the delivery of neural t‐PA to vessel walls. The intramural production of plasmin induced by this system represents a novel principle for the regulation of arterial matrix flexibility, especially in the media of densely innervated small arteries and resistance arterioles involved in the pathogenesis of stroke, hypertension, and vascular aging. Thus, the data suggest an important new interface between neuroscience and vascular biology that merits further exploration. J. Neurosci. Res. 53:443–453, 1998.

Sympathectomy decreases and adrenergic stimulation increases the release of tissue plasminogen activator (t‐PA) from blood vessels: Functional evidence for a neurologic regulation of plasmin production within vessel walls and other tissue matrices

Our recent morphologic studies indicated that peripheral nervous system (PNS) adrenergic neurons synthesize, transport, and store the serene protease, tissue plasminogen activator (t‐PA) in axon terminals, many of which innervate vessel walls. Sympathoadrenal stimulation induces a surge of t‐PA from vessel walls into the blood. The vascular endothelium, which constitutively secretes t‐PA into blood also has long been widely assumed to be the principal source of this stress‐induced release, but has not been verified as such. A neurologically regulated release from adrenergic stores could thus augment the known constitutive endothelial release. To functionally test this possibility, we quantitated the effects of guanethidine‐induced systemic sympathectomy on the basal and stimulated release of t‐PA from isolated vessel explants in superfused organ cultures. Moment‐to‐moment changes in the release rate were plotted from serial assays of the t‐PA free activity. The effects of endothelial and adventitial nerve plexus ablations were also tested. Sympathectomy induced 30–50% reductions in t‐PA release from both arterial and microvascular explants. An acute release induced by alpha‐1 adrenergic receptor stimulations was also strongly suppressed, as were basal levels of the circulating enzyme in vivo. Adventitial and endothelial ablations from normal large vessel explants produced greater reductions than small vessel endothelial ablations. Ganglion electrical stimulation also induced an acute microvascular release in vivo. These and past morphologic findings indicate a physiological infusion of t‐PA into the vessel walls, blood, and other innervated matricesby sympathetic neurons. J. Neurosci. Res. 57:680–692, 1999.

An in vitro model of leukocyte mediated injury to the corneal epithelium

To enhance efforts directed at unraveling the role and mechanisms of leukocytes in mediating injury to corneal epithelium, an isolated bovine corneal cup was developed and evaluated. Bovine peripheral leukocytes and lysates were added to the corneal epithelial surface of isolated cornea for various periods after which the degree of morphologic changes and cell damage were assessed using light and electron microscopy. Results of these studies indicate that leukocyte/epithelial cell interactions are characterized by five successive stages: (1) leukocyte adhesion to superficial layer of the epithelium, (2) leukocyte penetration beneath the superficial epithelium, (3) epithelial cell injury, (4) leukocyte phagocytosis of killed epithelial cells and (5) ulceration and total destruction of the full thickness of the epithelial layer. The above sequence appears to be both time and dose dependent; that is epithelial cells exposed to leukocytes for short periods (5-60 minutes) or to low dose levels (10(5) - 10(7) cells/ml) shows leukocyte adhesion and penetration beneath the superficial layer of the epithelium, (stage 1 and 2), while longer exposures (2-3 hours) or higher numbers of leukocytes (10(7) - 10(8) cells/ml), leads to deeper penetration of epithelium by leukocytes and epithelial injury (Stages 3,4,and 5). We also observed that direct contact of intact leukocytes with epithelial cells is apparently necessary to induce this type of injury. These findings demonstrate the ability of leukocytes to destroy corneal epithelial cells and the value of this new ocular model for studies of the basic immunology of ocular inflammation.

Enhancement of the recovery of rat hearts after prolonged cold storage by cyclocreatine phosphate

The present study determined whether the administration of cyclocreatine phosphate (CCrP) prior to ischemia can enhance the recovery of rat hearts hypo-thermically preserved for a prolonged period. Rats (n=6 per group) were injected intravenously with 1 ml saline or CCrP (500 mg/kg). After 2 hr, hearts were excised and arrested by an infusion of University of Wisconsin solution. Saline hearts were then incubated in 40 ml UW, while CCrP hearts were incubated in 40 ml UW containing 100 mg CCrP; a mixture that is now referred to as Hartford Hospital (HH) solution. After 6 hr of storage at 4°C, hearts were reperfused in the Langendorff mode for 15 min and then in the working heart mode for 30 min. Results indicated that the recovery of cardiac function—measured as aortic flow, coronary flow, cardiac output, stroke volume, and stroke work—was significantly better in CCrP group (50–55% baseline) compared with that of saline hearts (20–25%). Although no difference in enzyme leakage (i.e., creatine kinase) or lactate was detected between the two groups, the increase in heart weight after the initial 6-hr storage was significantly higher in saline hearts compared with that of CCrP hearts. Results of this study support the conclusion that CCrP treatment provides improved functional recovery after prolonged hypothermic preservation.

Tubular Inclusions in Macrophages in the Brain of a Patient with Acute Hemorrhagic Leukoencephalitis ( Weston-Hurst Syndrome)

A case history, biopsy findings, and autopsy findings of an unusually long-lasting case of acute hemorrhagic leukoencephalitis in a young woman are presented. Diagnosis by stereotactic biopsy of brain lesions seen on computed tomography and magnetic resonance imaging scans had been attempted previously. On histologic examination the biopsy showed sheets of macrophages, which were found to contain unusual tubular inclusions on electron microscopy. The nature of these inclusions is discussed.

Glomerular Spherical Electron Dense Deposits in a Patient Undergoing Long-Term Regional Heparinization

Spherical electron dense deposits in the glomerular capillary basement membranes and the mesangial matrix were observed in a patient undergoing long-term regional heparinization during treatment with continuous arteriovenous hemofiltration (CAVH). CAVH is a fairly new approach to renal replacement therapy and requires continuous infusion of heparin into the prefilter blood line. In order to limit systemic anticoagulation, protamine may be infused into the postfilter blood line. In the patient described, during 26 days of continuous treatment, 318,620 units of heparin and 5,204 mg of protamine had been infused. Ultrastructural studies of the kidneys obtained at autopsy revealed a striking resemblance between the electron dense deposits seen in this patient and the protamine-heparin complexes described in animal models. Heavy metals, including calcium, phosphorus, and aluminum were excluded by electron probe x-ray microanalysis.