Severe morbidity and mortality with breast milk associated cytomegalovirus infection.

Congenital cytomegalovirus (CMV) infection can cause significant morbidity and mortality in the newborn period. Postnatally acquired CMV infection has been thought to carry much less morbidity. We report 5 cases of severe morbidity and mortality in very low birth weight infants with postnatally acquired, breast milk associated CMV infection.

Spinal nerve ligation-induced activation of nuclear factor kappaB is facilitated by prostaglandins in the affected spinal cord and is a critical step in the development of mechanical allodynia.

This study investigated the effect of 5th and 6th lumbar nerve (L5/L6) spinal nerve ligation (SNL) on activated nuclear factor kappaB (NFkBa) in nuclear extracts from the lumbar dorsal horn of the rat, and its relationship to prostaglandin (PG)-dependent spinal hyperexcitability and allodynia 3 days later. Male Sprague-Dawley rats, fitted with intrathecal (i.t.) catheters, underwent SNL- or sham-surgery. Paw withdrawal threshold (PWT), electromyographic analysis of the biceps femoris flexor reflex, and immunoblotting of the spinal cord were used. Both allodynia (PWT

Grid-enabling medical image analysis.

Grids have emerged as a promising technology to handle the data and compute intensive requirements of many application areas. Digital medical image processing is a promising application area for grids. Given the volume of data, the sensitivity of medical information, and the joint complexity of medical datasets and computations expected in clinical practice, the challenge is to fill the gap between the grid middleware and the requirements of clinical applications. The research project AGIR (Grid Analysis of Radiological Data) presented in this paper addresses this challenge through a combined approach: on one hand, leveraging the grid middleware through core grid medical services which target the requirements of medical data processing applications; on the other hand, grid-enabling a panel of applications ranging from algorithmic research to clinical applications.

A battle over birth "control": legal and legislative employer prescription contraception benefit mandates.

Under the Pregnancy Discrimination Act (PDA), employers are prohibited from discriminating against women by treating pregnancy and childbirth different from other medical conditions. Employers who offer medical benefits to their employees have thus been required to cover pregnancy-related medical costs on the same terms as other medical coverage. The cost of prescription contraception, however, has generally not been covered by employer-sponsored medical plans, even while other prescription drugs were. This Note examines the recent case of Erickson v. Bartell Drug Co., which challenged this practice of excluding prescription contraception coverage as discriminatory under the PDA, and argues that further federal legislation is necessary to ensure the equal treatment of women in the workplace.

The release of spinal prostaglandin E2 and the effect of nitric oxide synthetase inhibition during strychnine-induced allodynia.

The removal of spinal glycinergic inhibition by intrathecal strychnine produces an allodynia-like state in rodents. Our objective was to measure spinal prostaglandin E2 (PGE2) release during strychnine-allodynia and examine the effects of Nomega-nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthetase. Under halothane, rats were fitted with intrathecal and spinal microdialysis catheters, and microelectrodes implanted into the locus coeruleus for measurement of catechol oxidation current (CAOC) using voltammetry. Animals were then administered urethane and treated as follows: 1) baseline control 10 min, intrathecal strychnine (40 microg) 10 min, 10 min of hair deflection, and 2) 10-min control followed by intrathecal strychnine (40 microg) with hair deflection for 60 min. Spinal dialysate samples were collected for PGE2 levels determined by using immunoassay. In separate experiments, the effect of intrathecal strychnine (40 microg) followed by hair deflection was studied in rats pretreated with intrathecal l-NOARG (50 nmol). After intrathecal strychnine, hair deflection significantly increased spinal PGE2 release (619% +/- 143%), locus coeruleus CAOC (181% +/- 6%), and mean arterial pressure (123% +/- 2%) P < 0.05. Pretreatment with intrathecal l-NOARG significantly inhibited strychnine-allodynia. In this model, hair deflection evokes spinal PGE2 release, locus coeruleus activation, and an increase in mean arterial pressure. L-NOARG pretreatment attenuated the locus coeruleus CAOC, a biochemical index of strychnine-allodynia, suggesting a mediator role of nitric oxide. A mediator role of nitric oxide is also implicated, helping to explain the pathophysiology of this allodynic pain.

Vagal afferent input determines the volume dependence of rat esophageal motility patterns.

The volume dependence of balloon distension-evoked esophageal rhythmic motor responses and their neural correlates was investigated in 72 urethane-anesthetized rats. With increasing balloon volume (75--200 microl), distal esophageal rhythmic contractions decreased in rate and became tonic in the range of 150--250 microl. This change in motor pattern involved only the striated musculature of the esophageal body and persisted after acute transection of the spinal cord at C(2). Impulse frequency in single vagal afferents of the distal esophagus increased with intraluminal pressure over the entire range of balloon volumes tested (50--300 microl). Distension-responsive neurons in the nucleus tractus solitarii showed rhythmic burst activity (type I), tonic excitation (type II), or inhibition followed by off bursts (type III). Increasing strength of stimulation changed type I responses to nonrhythmic but intensified type II and III responses. We conclude that load-dependent changes in distal esophagus motility pattern are encoded by vagal afferents alone and do not involve a spinal afferent input even at near-noxious stimulus strengths.

An acylatable residue of Hedgehog is differentially required in Drosophila and mouse limb development.

The Drosophila Hedgehog protein and its vertebrate counterpart Sonic hedgehog are required for a wide variety of patterning events throughout development. Hedgehog proteins are secreted from cells and undergo autocatalytic cleavage and cholesterol modification to produce a mature signaling domain. This domain of Sonic hedgehog has recently been shown to acquire an N-terminal acyl group in cell culture. We have investigated the in vivo role that such acylation might play in appendage patterning in mouse and Drosophila; in both species Hedgehog proteins define a posterior domain of the limb or wing. A mutant form of Sonic hedgehog that cannot undergo acylation retains significant ability to repattern the mouse limb. However, the corresponding mutation in Drosophila Hedgehog renders it inactive in vivo, although it is normally processed. Furthermore, overexpression of the mutant form has dominant negative effects on Hedgehog signaling. These data suggest that the importance of the N-terminal cysteine of mature Hedgehog in patterning appendages differs between species.

Coadministration of intrathecal strychnine and bicuculline effects synergistic allodynia in the rat: an isobolographic analysis.

Tactile allodynia can be modeled in experimental animals by acutely blocking spinal glycine or GABA(A) receptors with intrathecal (i.t.) strychnine (STR) or bicuculline (BIC), respectively. To test the hypothesis that glycine and GABA effect cooperative (supra-additive) inhibition of touch-evoked responses in the spinal cord, male Sprague-Dawley rats, fitted with chronic i.t. catheters, were used. Following i.t. STR, BIC, or STR + BIC, hair deflection evoked cardiovascular (increased blood pressure and heart rate), motor (scratching, kicking and rippling of the affected dermatomes), and cortical encephalographic responses. Hair deflection was without effect in i.t. saline-treated rats. Isobolographic analysis of STR (ED(50) = 25.1-36.9 microg), BIC (ED(50) = 0.5-0.6 microg), and BIC:STR combination (ED(50) = 0.026-0.034:2.6-3.4 microg) dose-response curves confirmed a supra-additive interaction between BIC and STR in this model. BIC-allodynia was reproduced by i.t. picrotoxin. Pretreatment with i.t. scopolamine, or i.t. muscarine had no effect. STR-allodynia was dose dependently inhibited by i.t. muscimol but not baclofen. The results of this study indicate that 1) glycine and GABA effect cooperative inhibition of low-threshold mechanical input in the spinal cord of the rat; and 2) BIC-allodynia arises from the blockade of GABA(A) receptors and is unrelated to any secondary anticholinesterase activity. The allodynic state induced by the blockade of glycine or GABA receptors is clearly exacerbated by the removal of both inhibitory systems. Their combined loss after neural injury may explain the exaggerated sensitivity to and subsequent miscoding of tactile information as pain.

Some distal limb structures develop in mice lacking Sonic hedgehog signaling.

Patterning of the limb is coordinated by the complex interplay of three signaling regions: the apical ectodermal ridge (AER), the zone of polarizing activity (ZPA), and the non-ridge limb ectoderm. Complex feedback loops exist between Shh in the ZPA, Bmps and their antagonists in the adjacent mesenchyme, Wnt7a in the dorsal ectoderm and Fgfs in the AER. In contrast to the previously reported complete absence of digits in Shh(-/-) mice, we show that one morphologically distinct digit, with a well-delineated nail and phalanges, forms in Shh(-/-) hindlimbs, while intermediate structures are severely truncated and fused. The presence of distal autopod elements is consistent with weak expression of Hoxd13 in Shh(-/-) hindlimbs. Shh(-/-) forelimbs in contrast have one distal cartilage element, a less-well differentiated nail and fused intermediate bones. Interestingly, Ihh is expressed at the tip of Shh mutant limbs and could account for formation of distal structures. In contrast to previous studies we also demonstrate that Shh signaling is required for maintenance of normal Fgf8 expression, since expression of Fgf8, unlike some other AER marker genes, is rapidly lost from anterior to posterior after E10.5, with only a small domain of Fgf8 expression remaining posteriorly. Furthermore, loss of expanded Fgf8 expression is paralleled by a collapse of the handplate. Our data show that development of most intermediate elements of the hindlimb skeleton are Shh-dependent, and that Shh signaling is required for anterior-posterior expansion of the AER in both limbs and for the subsequent branching of zeugopod and autopod elements. Finally, we show that Shh is also required for outgrowth of the limb ectoderm and thus for the formation of a distinct limb compartment.

Fibroma induction in rat skin following single or multiple doses of 1.0 GeV/nucleon 56Fe ions from the Brookhaven Alternating Gradient Synchrotron (AGS).

Rat skin was exposed to the plateau region of the 1.0 GeV/nucleon 56Fe beam at the Brookhaven AGS. Rats were irradiated or not with single of split doses of 56Fe or argon; some 56Fe-exposed rats were fed 250 ppm retinyl acetate continuously in the lab chow beginning 1 week before irradiation. All lesions were noted, photographed and identified for eventual histological diagnosis. The preponderance of the tumors so far are fibromas. The data show that single doses of 56Fe ions are 2 or 3 fold more effective than argon in producing tumors at 4.5 Gy but are about equally effective at 3.0 Gy and 9.0 Gy. The presence of 250 ppm retinyl acetate in the lab chow reduced the incidence of tumors by about 50-60% in comparison to groups exposed only to the radiation. These are preliminary findings based on only about one-fourth the eventual number of tumors expected.

Two lineage boundaries coordinate vertebrate apical ectodermal ridge formation.

Proximal-distal outgrowth of the vertebrate limb bud is regulated by the apical ectodermal ridge (AER), which forms at an invariant position along the dorsal-ventral (D/V) axis of the embryo. We have studied the genetic and cellular events that regulate AER formation in the mouse. In contrast to implications from previous studies in chick, we identified two distinct lineage boundaries in mouse ectoderm prior to limb bud outgrowth using a Cre/loxP-based fate-mapping approach and a novel retroviral cell-labeling technique. One border is transient and at the limit of expression of the ventral gene En1, which corresponds to the D/V midline of the AER, and the second border corresponds to the dorsal AER margin. Labeling of AER precursors using an inducible Cre showed that not all cells that initially express AER genes form the AER, indicating that signaling is required to maintain an AER phenotype. Misexpression of En1 at moderate levels specifically in the dorsal AER of transgenic mice was found to produce dorsally shifted AER fragments, whereas high levels of En1 abolished AER formation. In both cases, the dorsal gene Wnt7a was repressed in cells adjacent to the En1-expressing cells, demonstrating that signaling regulated by EN1 occurs across the D/V border. Finally, fate mapping of AER domains in these mutants showed that En1 plays a part in positioning and maintaining the two lineage borders.

Effects of vagal cooling on esophageal cardiovascular reflex responses in the rat.

Distension of the distal esophagus in the anesthetized rat causes a vagally-mediated arterial pressor and tachycardia response. To investigate the nature of viscerosensory fibers in the afferent limb of this reflex, the present study was carried out in urethane-anesthetized rats that were subjected to graded cooling of both cervical vagal trunks in situ. Distal esophageal distension was applied for 20 s by means of a water-filled high compliance balloon. Vagal cooling to 9 degrees C abolished pressor responses and unmasked a depressor component during maximal distension. Cooling to 7.5 degrees C blocked this inhibitory component, well above the temperature known to block C-fibers. We conclude that the cardiovascular response to esophageal distension is triggered via at least two subpopulations of A(delta) type vagal afferents that project to brain stem nuclei regulating central vasomotor tone.

Distal and deglutitive inhibition in the rat esophagus: role of inhibitory neurotransmission in the nucleus tractus solitarii.

BACKGROUND & AIMS: This study aimed to show the presence of deglutitive and distal inhibition in the rat esophagus and to differentiate the underlying neural mechanisms. METHODS: Under urethane anesthesia, the pharyngoesophageal tract was fitted with water-filled balloons for luminal distention and pressure recording. Neural activity was recorded in the nucleus tractus solitarii subnucleus centralis and rostral nucleus ambiguous. RESULTS: Distal esophageal distention evoked both rhythmic local contractions and burst discharges of ambiguous neurons that were simultaneously inhibited by a swallow or proximal esophageal distention. In subnucleus centralis interneurons, type I rhythmic burst discharges correlated with distal esophageal pressure waves and were suppressed by midthoracic esophageal distention; type II non-rhythmic excitatory responses, like type III inhibitory responses, were evoked by distention of either the thoracic or distal esophagus. When applied to the surface of the solitarius complex, bicuculline and, less effectively, strychnine suppressed distal inhibition, and 2-(OH)-saclofen and 3-aminopropylphosphonic acid were ineffective. None of the drugs tested, including systemic picrotoxin, affected deglutitive inhibition. CONCLUSIONS: Distal and deglutitive inhibition are present in the rat esophagus. The former, unlike the latter, depends on activation of ligand-gated chloride channels associated with subnucleus centralis premotor neurons. Inhibitory aminoacidergic local interneurons are a probable source of type II responses.

A rat small bowel transplant model of chronic rejection: histopathologic characteristics.

BACKGROUND: The major impediment to long-term success in solid organ transplantation is the development of chronic rejection (CR). The vascular lesion of CR, transplant vascular sclerosis (TVS) is characterized by neointimal smooth muscle cell proliferation, and is driven by both immune- and nonimmune-mediated mechanisms. Although the features of chronic heart and kidney allograft rejection have been well characterized, the more immunogenic small bowel allograft has not received similar study. METHODS: F344 small bowel (SB) was transplanted heterotopically into Lewis recipients that were treated with low-dose Cyclosporine A for 15 days. Lewis recipients of F344 or Lewis SB grafts without immunosuppression, served as controls. Grafts were assessed histologically when recipients showed clinical signs of rejection or at predetermined time points. The immunological components involved in the chronic rejection process were evaluated by immunohistochemical staining. RESULTS: All SB allografts (100%) developed histologic evidence of CR Cyclosporine A. TVS was seen in 36 of the 46 (78%) of these allografts. The median time to develop TVS was 45 days. Immunohistochemical staining of chronically rejected grafts showed infiltration predominantly by CD4+ cells and macrophages, uniform up-regulation of class II MHC molecule expression, moderate to intense ICAM-1 staining in grafts harvested at postoperative day 45, and uniform neointimal cell staining for smooth muscle cell alpha-actin in the TVS lesions. CONCLUSIONS: This F344 to Lewis SB transplant model is a useful model that reproduces significant features of CR. The highly immunogenic nature of the SB allografts allows this model to serve as a stringent test for protocols designed to prevent CR.

Activation of the rostral ventrolateral medulla in an acute anesthetized rodent strychnine model of allodynia.

UNLABELLED: After the administration of intrathecal strychnine, allodynia is manifested as activation of supraspinal sites involved in pain processing and enhancement of cardiovascular responses evoked by normally innocuous stimuli. The objective of this study was to investigate the effect of strychnine-induced allodynia on adrenergic neuronal activity in the C1 area of the rostral ventrolateral medulla (RVLM), a major site involved in cardiovascular regulation. The effect of intrathecal strychnine (40 microg) or saline followed by repeated hair deflection to caudal lumbar dermatomes in the urethane-anesthetized rat was assessed by measuring voltammetric changes in the RVLM catechol oxidation current (CA x OC), mean arterial pressure (MAP), and heart rate (HR). After the administration of intrathecal strychnine, hair deflection evoked a significant and sustained increase in the RVLM CA x OC and MAP (peak 146.4%+/-5.6% and 159%+/-18.4% of baseline, respectively; P < 0.05). There was a nonsignificant increase in HR (peak 128%+/-8.2%). In the absence of hair deflection, there was no demonstrable change. Intrathecal saline-treated rats failed to demonstrate changes in RVLM CA x OC, MAP, or HR. In the present study, we demonstrated that, after the administration of intrathecal strychnine, innocuous hair deflection evokes temporally related neuronal activation in the rat RVLM and an increase in MAP. This suggests that the RVLM mediates, at least in part, the cardiovascular responses during strychnine allodynia. IMPLICATIONS: Neural injury-associated pain, as manifested by allodynia, is resistant to conventional treatment. In a rat model of allodynia, we demonstrated activation of the brain region involved in sympathetic control. Innovative therapies that target this region may be successful in managing this debilitating condition.

Architectural organization of filiform papillae in normal and black hairy tongue epithelium: dissection of differentiation pathways in a complex human epithelium according to their patterns of keratin expression.

BACKGROUND: An inadequate understanding of the complex morphologic characteristics of human filiform papillae has hampered the histopathological characterization of disorders affecting tongue keratinization. To better define the 3-dimensional cytoarchitecture of tongue epithelium, we performed detailed immunohistochemical analyses of normal and black hairy tongue tissues using a panel of antikeratin antibodies. OBSERVATIONS: The dome-shaped base of the human filiform papilla (primary papilla) is surmounted by 3 to 8 elongated structures (secondary papillae). These secondary papillae are composed of a central column of epithelial cells expressing hair-type keratins and an outer rim of cells expressing skin-type keratins. The epithelium overlying the primary papillae and between the individual primary papillae express esophageal-type keratins. In black hairy tongue disease, there is a marked retention of secondary papillary cells expressing hair-type keratins. CONCLUSIONS: Using a panel of antikeratin probes, we define the precise topographical localization of cell populations undergoing 3 distinct differentiation programs in dorsal tongue epithelium. Comparative analyses of black hairy tongue specimens indicate that defective desquamation of the cells in the central column of filiform papillae results in the formation of highly elongated, cornified spines or, "hairs"--the hallmark of this disease.

Spinal action of ketorolac, S(+)- and R(-)-ibuprofen on non-noxious activation of the catechol oxidation in the rat locus coeruleus: evidence for a central role of prostaglandins in the strychnine model of allodynia.

BACKGROUND: Blockade of spinal glycine receptors with intrathecal strychnine produces an allodynia-like state in the anesthetized rat. Innocuous hair deflection in the presence of intrathecal strychnine induces a nociceptive-like activation of catechol oxidation in the locus coeruleus and enhances cardiovascular responses. Because prostaglandins play a central role in augmenting pain, this study evaluated the effect of intrathecal nonsteroidal antiinflammatory drugs in strychnine-induced allodynia. METHODS: In urethane-anesthetized rats, changes in catechol oxidation in the locus coeruleus, measured using in vivo voltammetry, and cardiovascular parameters evoked by hair deflection of caudal dermatomes were determined after strychnine (40 microg) or saline were administered intrathecally. Subsequently, the effects of 30 microg ketorolac, 10 microg S(+)-ibuprofen, and 10 microg R(-)-ibuprofen administered intrathecally were evaluated. RESULTS: After strychnine was administered intrathecally, hair deflection evoked an increase in the locus coeruleus catechol oxidation (peak, 149.7+/-7.2% of baseline) and mean arterial blood pressure (peak, 127.5+/-3.8% of baseline). These responses were not observed after saline was administered intrathecally. All hair deflection-evoked, strychnine-dependent peak responses were attenuated significantly with intrathecally administered ketorolac and S(+)-ibuprofen but not with R(-)-ibuprofen. CONCLUSIONS: Locus coeruleus catechol oxidation is a sensitive biochemical index of strychnine-induced allodynia and is correlated temporally with the cardiovascular responses evoked by hair deflection during spinal glycinergic inhibition. The ability of intrathecally administered ketorolac and S(+)-ibuprofen, but not R(-)-ibuprofen, to suppress the locus coeruleus catechol oxidation and cardiovascular peak responses evoked during strychnine-induced allodynia provide evidence that central prostaglandins play an important role in the abnormal sensory processing of strychnine-induced allodynia.

Inhibition of strychnine-allodynia is mediated by spinal adenosine A1- but not A2-receptors in the rat.

Intrathecal (i.t.) strychnine produces localized allodynia in the rat without peripheral or central nerve injury. Intrathecal CPA (A1-selective agonist) and CGS-21680 (A2-selective agonist) dose-dependently inhibited strychnine-allodynia but with a 50-fold difference in potency (0.02-0.07 vs. 2.7-3.1 microgram, respectively). The anti-allodynic effect of CPA and CGS was completely blocked by pretreatment with the A1-selective antagonist, DPCPX (10 microgram i.t. ), but unaffected by the A2-selective antagonist, CSC (2 microgram i.t. ). The results indicate that spinal A1-, but not A2-, receptors modulate abnormal somatosensory input in the strychnine model, and suggest a difference in spinal purinergic modulation in injury vs. non-injury models of allodynia.