Distribution of cocaine- and amphetamine-regulated transcript peptide in the guinea pig intrinsic cardiac nervous system and colocalization with neuropeptides or transmitter synthetic enzymes.

This study was conducted to establish the presence of cocaine- and amphetamine-regulated transcript peptide (CARTp) immunoreactivity in neurons and fibers within guinea pig atrial whole-mount preparations containing the intrinsic cardiac ganglia. Many cardiac ganglia, but not all, in a given whole-mount preparation, were innervated by CARTp-immunoreactive (IR) fibers. Following explant culture of whole mounts for 72 hours, the CARTp-IR fiber networks were absent, but the number of CARTp-IR neurons was increased markedly. These observations suggested that the majority of the CARTp-IR fibers in the intracardiac ganglia were derived from sources extrinsic to the heart. In control whole-mount preparations, very few CARTp-positive neurons were present. The few intrinsic CARTp-IR neurons also exhibited choline acetyltransferase (ChAT) immunoreactivity, indicating that they make up a small subpopulation of cholinergic postganglionic neurons. Some CARTp-IR neurons also exhibited nitric oxide synthase (NOS) immunoreactivity, indicating that they were nitrergic as well. We compared the immunohistochemical staining patterns of CARTp-IR fibers with the staining patterns of a number of other neurotransmitters or neurotransmitter synthetic enzymes that mark specific extrinsic inputs. The CARTp-IR fibers were not immunoreactive for ChAT, tyrosine hydroxylase, calcitonin gene-related peptide, or substance P. However, virtually all CARTp-IR fibers exhibited immunoreactivity to neuronal NOS (a marker for nitric oxide-producing neurons). CARTp-IR cells and NOS-IR cells were present in the nodose ganglia. In addition, CARTp-IR neurons in the nodose also were stained positively for NADPH-diaphorase. Thus, we propose that most CARTp-IR fibers within the guinea pig intrinsic cardiac ganglia are vagal afferent fibers that also contain NOS.

Chorda tympani nerve stimulation evokes Fos expression in regionally limited neuron populations within the gustatory nucleus of the solitary tract.

The distribution of neurons in the rostral nucleus of the solitary tract (rNST) that respond to gustatory input from the anterior tongue was visualized by Fos protein immunohistochemistry following electrical stimulation of the chorda tympani (CT) nerve in rats. Maps of Fos-immunoreactive (Fos-ir) neurons were compared with the distribution of CT afferent terminal fields labeled by transganglionic transport of rhodamine-dextran in a separate group of animals. The primary concentration of Fos-ir neurons localized in register with the major terminal fields of CT afferent fibers, in the central third of the rostral 1.0 mm of the NST ipsilateral to the stimulated nerve. A similar correspondence in location and degree of labeling of Fos-ir neurons and afferent terminals was observed in the ipsilateral dorsal spinal trigeminal complex (Sp5) pars caudalis, near the obex, and the Sp5 pars oralis near the rostral pole of the rNST. Thus, the magnitude of Fos upregulation in brainstem targets of the CT nerve having chemosensory or nociceptive function, was proportional to the relative density of the CT afferent input. This correspondence, and the absence of labeling in neurons known to be one additional synapse away from the afferent input within gustatory or oral reflex pathways, suggests that the cell map obtained represents mainly neurons that are directly activated via primary afferent synapses from CT fibers. The availability of a method to histochemically identify a population of putative second-order taste neurons will facilitate analysis of the cellular/molecular properties of these neurons and of synaptic circuitry in the rNST.

Equal care ensures equal survival for African-American women with cervical carcinoma.

BACKGROUND: [corrected] It was the purpose of this study to investigate whether race is an independent prognostic factor in the survival of patients with cervical carcinoma in a health care system with minimal racial bias, and few barriers to access to care. METHODS: Records for patients with a diagnosis of invasive cervical carcinoma from 1988 to 1999 were obtained from the Automated Central Tumor Registry for the United States Military Health Care System. Clinical data including race, age at diagnosis, histology, grade, stage, socioeconomic status, treatment modality, and survival also were obtained. Survival analysis was performed with Kaplan-Meier survival curves. RESULTS: One thousand five hundred fifty-three patients were obtained for review. Sixty-five percent of patients were Caucasian, and 35% were minorities. Of the minorities, 29% were African Americans (AAs). Mean age of diagnosis was similar among AAs and Caucasians, 44 and 42 years, respectively. There was no statistically significant difference between the distribution of age, stage, grade, or histology between Caucasians and AAs. Forty-six percent of patients were treated with surgery and 56% with radiation therapy, with no difference in type of treatment between the Caucasian and AA groups. Five- and 10-year survival rates for Caucasians and AAs were 75%, and 76%, and 64% 65% (P = 0.59), respectively. CONCLUSIONS: In an equal access, unbiased, nonracial environment, race is not an independent predictor of survival for patients with cervical carcinoma. This study has shown, for the first time to the authors' knowledge, that when they receive equal treatment for cervical carcinoma, AA women's survival can approach that of their nonminority counterparts (75% at 10 years).

Identification of members of the Wnt signaling pathway in the embryonic pituitary gland.

Prop1 is one of several transcription factors important for the development of the pituitary gland. Downstream targets of PROP1 and other critical pituitary transcription factors remain largely unknown. We have generated a partial expression profile of the developing pituitary gland containing over 350 transcripts, using cDNA subtractive hybridization between Prop1(df/df) and wild-type embryonic pituitary gland primordia. Numerous classes of genes including transcription factors, membrane associated molecules, and cell cycle regulators were identified in this study. Of the transcripts, 34% do not have sequence similarity to known genes, but are similar to ESTs, and 4% represent novel sequences. Pituitary gland expression of a number of clones was verified using in situ hybridization. Several members of the Wnt signaling pathway were identified in the developing pituitary gland. The frizzled2 receptor, Apc, beta-catenin, groucho, and a novel isoform of TCF4 (officially named Tcf7l2) were identified in developing pituitary libraries. Three N-terminal alternatively spliced Tcf7l2 isoforms are reported here, each of which lacks a DNA-binding domain. Functional studies indicate that these isoforms can act as endogenous inhibitors of Wnt signaling in some contexts. This is the first report of Tcf7l2 and Fzd2 expression in the developing pituitary. These molecules may be important in mediating Wnt signaling during pituitary ontogeny. We expect other transcripts from these libraries to be involved in pituitary gland development.

Hypothalamic orexin A-immunoreactive neurons project to the rat dorsal medulla.

Retrograde tract tracing combined with immunohistochemical techniques were used to identify the origin of orexin A-immunoreactive (OrA-ir) fibers in the rat medulla. One to 5 days following injection of the fluorescent dye Fluorogold into the dorsal medulla, labeled neurons were found in the lateral half of the lateral hypothalamus, paraventricular, perifornical, dorsomedial, dorsal and posterior hypothalamic nuclei. Labeling the same sections with OrA antisera revealed a concentration of OrA-ir neurons in the perifornical and dorsomedial regions of the tuberal hypothalamus. A maximum of 10% of Fluorogold-labeled hypothalamic neurons were OrA-ir and 15% of OrA-ir hypothalamic neurons contained Fluorogold. Our results demonstrate that a fraction of OrA-ir neurons in the tuberal hypothalamus project to areas of the medulla that are involved in autonomic functions.

Clinicopathologic variables predictive of residual dysplasia after cervical conization.

OBJECTIVE: To evaluate the clinicopathologic variables that are important for predicting residual dysplasia after cervical conization or the loop electroexcisional procedure. STUDY DESIGN: A retrospective review of 80 cases was performed on patients with squamous dysplasia in the conization specimen, endocervical curettage (ECC) performed immediately after resection, margin status reported by the pathologist and adequate postprocedure follow-up. RESULTS: Twelve patients had residual dysplasia. No case progressed to invasive carcinoma. A multivariate analysis was performed with presence or absence of residual dysplasia as the dependent variable and patient age, type of procedure (cold knife conization or loop excision), grade of dysplasia, margin status and ECC status as independent variables. Margin status was the strongest predictor of residual disease, followed by ECC status. Patient age had a minimal association with persistence. Of the 12 patients with residual dysplasia, 11 had a positive margin, and 8 had a positive ECC. Only 38% of patients with a positive margin had residual disease, but 67% with a positive margin and ECC had residual dysplasia. CONCLUSION: Margin status and ECC are useful in predicting residual dysplasia after conization.

Short-term plasticity in primary somatosensory cortex of the rat: rapid changes in magnitudes and latencies of neuronal responses following digit denervation.

Recordings were made from neurons in primary somatosensory (SmI) forepaw cortex of rats to study the time course of changes in responses beginning immediately following denervation (ligation) of a single digit. Before denervation, neuronal receptive fields (RFs) defined by tactile stimulation varied in size from small regions of one digit to larger areas covering several digits and palmar pads. With electrical stimulation, most neurons responded best to one (on-focus) digit and less to other (off-focus) digits; on-focus stimulation yielded more spikes per stimulus and shorter spike latencies (Lmin) than did off-focus stimulation. After ligation of the on-focus digit, most neurons showed increased responsiveness to stimulating one or several off-focus digits and palmar regions of the forepaw: (1) tactile stimulation showed that the RFs of all but one neuron expanded to include previously "ineffective" skin regions, such as digits or palmar pads adjoining the original RF; (2) electrical stimulation usually evoked stronger responses from neighboring off-focus digits and sometimes elicited novel responses from previously ineffective digits--seven of ten neurons showed increases in spikes per stimulus, which tended to approach stable values within 60-90 min after denervation; three of ten neurons showed decreases in Lmin with time, but most revealed no significant changes. These results suggest that dynamic response properties, as well as RFs, of SmI cortical neurons can be modified rapidly by blocking afferent input from dominant on-focus skin regions. RFs expand and novel responses appear, with concomitant increases in response magnitude and, in some cases, decreases in response latency over time. These findings seem to reflect a rapid increase in synaptic efficacy of weak or previously ineffective inputs from cutaneous afferent nerve fibers.

Abnormal cardiac sensory innervation associated with experimentally induced, electrocardiographic long QT intervals in chick embryos.

Prolongation of the QT interval in the ECG can be induced in d 17 chick embryos by ablating the nodose placode on the right side on d 1 of development. The nodose placode contains the precursor cells which form the neurons of the nodose (inferior vagal) ganglion. Neurons in this ganglion provide sensory innervation to the heart and other viscera. In this study, we measured ganglion volume and neuron size and number in the right and left nodose ganglia in d 17 experimental and control embryos from whom electrocardiograms had been obtained. A significant reduction in the number of neurons present in the right nodose ganglion, relative to the left ganglion, was evident in all embryos with abnormally prolonged QT intervals. Embryos with prolonged QT, as well as lesioned embryos who demonstrated normal.QT on d 17, also had abnormally small neurons in both right and left nodose ganglia, indicating an additional nonspecific, perhaps permissive, effect of the lesion. These results suggest that abnormal development of the sensory innervation of the heart may be an important link in the chain of events leading to the developmental long QT syndrome expressed by these embryos.

Surgical predictors of para-aortic metastases in early-stage cervical carcinoma.

Radical pelvic surgery for cervical carcinoma is contraindicated in the presence of para-aortic node metastases. However, the incidence of para-aortic nodal involvement is very low in early-stage disease. Therefore, it may not be necessary to subject all patients to para-aortic lymphadenectomy prior to radical hysterectomy. Medical records for 408 patients with early-stage cervical carcinoma treated at the Pennsylvania State University-M.S. Hershey Medical Center were reviewed to ascertain if clinical factors can be utilized intraoperatively to accurately predict those patients at minimal risk for para-aortic lymph node metastases. The presence of clinically suspicious (abnormally enlarged or firm) pelvic or para-aortic lymph nodes or extracervical spread of tumor at the time of exploration were significant predictors of para-aortic metastases (P < 0.001). The majority of patients (85%) had none of these risk factors, and no patient had para-aortic metastases in the absence of these predictors. Suspicious pelvic or para-aortic lymph nodes were present in the minority of patients (15%) and identified all patients with para-aortic metastases. Therefore, para-aortic lymphadenectomy may be safely omitted at the time of exploration for radical hysterectomy in the absence of enlarged or abnormally firm pelvic or para-aortic lymph nodes. In the presence of either of these factors or extracervical spread of disease a para-aortic lymphadenectomy is necessary to rule out metastases.

Compensatory responses and development of the nodose ganglion following ablation of placodal precursors in the embryonic chick (Gallus domesticus).

The nodose ganglion is the distal cranial ganglion of the vagus nerve which provides sensory innervation to the heart and other viscera. In this study, removal of the neuronal precursors which normally populate the right nodose ganglion was accomplished by ablating the right nodose placode in stage 9 chick embryos. Subsequent histological evaluation showed that in 54% of lesioned embryos surviving to day 6, the right ganglion was absent. Most embryos surviving to day 12, however, had identifiable right ganglia. In day 12 embryos, the right ganglion which developed was abnormal, with ganglion volume and ganglion cell diameter reduced by 50% and 20%, respectively, compared to control ganglia. To investigate the source of the neuron population in the regenerated ganglion, we combined nodose placode ablation with bilateral replacement of chick with quail "cardiac" neural crest (from mid-otic placode to somite 3). These cells normally provide only non-neuronal cells to the nodose ganglion, but produce neurons in other regions. At day 9, quail-derived neurons were identified in the right nodose ganglia of these chimeras, indicating that cardiac neural crest cells can generate neurons in the ganglion when placode-derived neurons are absent or reduced in number. On the other hand, we found that "sympathetic" neural crest (from somites 10 to 20) does not support ganglion development, suggesting that only neural crest cells normally present in the ganglion participate in reconstituting its neuronal population. Our previous work has shown that right nodose placode ablation produces abnormal cardiac function, which mimics a life-threatening human heart condition known as long QT syndrome. The present results suggest that the presence of neural crest-derived neurons in the developing right nodose ganglion may contribute to the functional abnormality in long QT syndrome.

Developmental study of the long QT with deafness syndrome in the chick embryo: cochlear pathology.

Developmental abnormalities of the peripheral auditory structures in an experimental animal model of the cardio-auditory (long QT with deafness) syndrome are described. Prolonged QT intervals in the electrocardiogram and deafness were induced in chick embryos by removal of tissue in the region of the right nodose and otic placodes on the first day of incubation. Electrocardiographic recordings, cochlear potential and brainstem auditory evoked responses were recorded in late embryonic life (E17), and used to identify embryos with long QTs and deafness. External and middle ears were evaluated under a dissecting microscope. Inner ears were evaluated in histological sections. Anomalies of the external and middle ears, such as the external auditory meatus, tympanic membrane and stapes, were attributed to disturbance of neural crest development. Anomalies of the inner ear, such as a complete absence of the cochlear duct and auditory nerve, or decreased length of the basilar papilla, were attributed to disturbance of otic placode development. The fact that a small lesion in the region of the nodose and otic placodes during early development in the chick animal model can produce a long QT interval in the electrocardiogram and deafness suggests that abnormal development in this region early in development might be the underlying cause of the human syndrome.

Developmental characteristics of the chick nodose ganglion.

Morphometric studies were carried out on the chick nodose ganglion between day 5 of incubation and 2 weeks after hatching. Previous findings showed that ablation of the nodose placode, the locus of precursor cells of nodose ganglion sensory neurons, results in abnormal cardiac function, and that these precursors can be induced to migrate abnormally to the heart and express abnormal phenotypes there, following cardiac neural crest ablation. These results prompted us to investigate further the normal development of nodose ganglion neurons. We find that the major period of neuron generation from placodal precursor cells in the ganglion occurs prior to day 5 of incubation. The loss of more than half of these neurons takes place between embryonic days 5 and 20, while neuron and ganglion sizes increase dramatically. Myelination is not seen at day 12 of incubation, but is present on day 15. Neurons continue to develop after hatching (day 21), reaching their adult size by 2 weeks after hatching. Unexpectedly, we found that the number of neurons increases after hatching, reaching the adult level of 62% more than embryonic day-20 numbers by 2 weeks after hatching. The mechanisms underlying the increase in neuron number after hatching are unexplained and require further investigation.

Adenosquamous carcinoma of the cervix: prognosis in early stage disease treated by radical hysterectomy.

The prognosis of adenosquamous carcinoma of the cervix compared to the pure cell types of this disease is a controversial issue. Survival rates vary widely among published series, with some authors finding the prognosis to be much worse and others finding it to be equal. We have studied a group of 290 patients, all of whom had the diagnosis of stage IB or IIA cervical cancer, and all of whom were treated by radical hysterectomy and bilateral pelvic and paraaortic lymphadenectomy. The pathology specimens were reviewed for every case. Median follow-up for all living patients was 73 months. Forty-five patients (15.5%) had adenosquamous histology, 220 (75.9%) had squamous cell, and 25 (8.6%) had adenocarcinoma. By X2, there was no significant difference among the three groups with regard to race, economic status, number of grade 3 lesions, number with positive pelvic lymph nodes, number with positive margins, stage distribution (IB vs IIA), or number of recurrences. Using Student's t test, there was no significant difference between any combination of two groups with regard to mean patient age, mean depth of invasion, or mean tumor size. Estimated disease-free survival and overall survival were not different among the three cell types. We conclude that for early stage cervical cancer treated by radical hysterectomy, the adenosquamous cell type does not carry a worse prognosis than either of the pure cell types.

Cerebral response to pyramidal tract stimulation in wood rats and its relation to laboratory rats.

The cerebral response evoked by stimulation of the bulbar pyramidal tract in wood rats, like that of laboratory rats, consisted of a small alpha wave, almost obscured by a very large, superimposed r wave. The alpha wave behaved like a purely antidromic response, whereas the r wave behaved like a postsynaptic response, including a marked variability in amplitude on repeated trials. The contralateral forepaw and hindpaw motor sites mapped onto the somatic sensory foci for these two paws; further examination showed that the somatic sensory and motor representations were largely superimposed. An incipient sagittal fissure 1.5 mm lateral to the midline marked the boundary between limbic and neocortex. Because of their structural similarities and their differences in somatic sensory and motor organization, wood rats and laboratory rats are prime subjects for comparative study of the role of amalgamated and separate sensory and motor cortices in regulating movement and behavior.

Discrimination among odorants by single neurons of the rat olfactory bulb.

1. Intracellular and extracellular recordings were made from rat olfactory bulb mitral and tufted cells during odor stimulation and during electrical stimulation of the olfactory nerve. Neurons were identified by horseradish peroxidase injections and/or antidromic activation. The presentation of multiple concentrations of at least one odorant in a cyclic artificial sniff paradigm, as reported previously (10), allowed the study of odor responses. This approach was extended to multiple odorants to compare their concentration-response profiles. This procedure avoids the problems of interpretation resulting from nonequivalence of the effective concentrations of different odorants used as stimuli that have characterized previous studies of odor quality effects. Comparisons of intracellular events and responses to electrical stimulation with the odor-induced spike train activity allow us to begin to delineate the local circuitry involved in generating odor-induced responses. 2. The concentration-response profiles of the 72 cells in the present study are comparable to those previously reported for output neurons of the olfactory bulb, showing ordered changes in the temporal patterning of spike activity with step changes in odor concentration. However, eight of the neurons exhibited inhibitory responses to lower concentrations, but excitation, at similar latency, to higher concentrations of the same odorant. These data emphasize that to study pattern changes induced by changing odor quality the influence of stimulus intensity must also be carefully examined. The data also provide evidence that the temporal pattern evoked by an odorant is probably not in itself the code for odor quality recognition. 3. Complete concentration-response profiles, including subthreshold concentrations, to more than one odorant show that, although responses to the different odorant can evolve systematically with concentration, the responses to different odorants can evolve through very different patterns. For example, in some cells, the response patterns to different odors were complementary in form. These results demonstrate that the patterned responses of olfactory bulb neurons can reflect changes in odor quality as well as intensity. 4. Intracellular recording was employed to compare the temporal patterning of spikes during odor stimulation with membrane potential changes. In some cases, the spike pattern was closely correlated with apparent postsynaptic potentials. However, there were several clear exceptions. In five cells, a prominent hyperpolarization, seen in the first sniff of a series of 10 consecutive sniffs, was associated with pauses in spike activity. In the following

Olfactory bulb responses to odor stimulation: analysis of response pattern and intensity relationships.

Extracellular recordings were made from mitral cells, tufted cells, and presumed glomerular layer and external plexiform layer interneurons of the olfactory bulb of anesthetized rats during odor stimulation. Intensity responses of these cells were studied by presenting a series of six or seven concentrations, spanning a range greater than two log units, in a cyclic artificial sniff paradigm, which produced repeated response measures at each concentration. Experiments focused on obtaining a complete intensity series, including interspersed unstimulated spontaneous activity records, for a single odorant (usually amyl acetate), but concentration responses to other odorants were tested when possible. Odor responses of 46 cells were studied with two approaches. Response form was examined in an attempt to define response classes based on qualitative characteristics of the temporal pattern of response. Assessment of response magnitude was attempted, in order to construct stimulus-response functions for each cell, independent of response form. As previously reported for olfactory bulb cells, the cells in our sample responded to odor stimulation with spike trains of a variety of temporal patterns, consisting of excitatory and inhibitory components that were frequently recognizable in the responses of a cell across a range of concentrations. However, response patterns usually changed significantly with concentration, such that response form across the concentration range could not be predicted from the response at any one concentration. Responses of different cells were sometimes similar to each other in form at one concentration and quite different from each other in the rest of their concentration-response profiles. Classification of response profiles into discrete types, based on consistency of response form throughout the profile, was therefore not feasible. In agreement with other reports, response of a single cell to different odorants sometimes showed similar forms and sometimes showed very different forms across the concentration-response profiles. Since the response form depends on the stimulus intensity as well as the stimulus quality, characterization of response magnitude and of the pattern of response to different odors require testing with a series of stimulus concentrations. Because odor responses consisted of temporally patterned spike trains, whose components changed in complex ways with stimulus intensity, it was not possible to quantify response magnitude by measuring characteristics of particular response components or counting mean frequency.(ABSTRACT TRUNCATED AT 400 WORDS)

Antidromic response to medullary pyramid stimulation in rats and its relation to that in cats.

The response evoked in the cerebral cortex of laboratory rats after stimulation of the medullary pyramid is surface-positive. It begins 0.9-1.6 ms after the stimulus, attains peak amplitude (up to 2 mV) in 0.8-1.2 ms and lasts 2-4 ms. It occurs throughout the anterior two-thirds of the dorsal cortex and is largest lateral to bregma, with a secondary maximum in the somatosensory area II. Although it depends on antidromic conduction in pyramidal tract fibers for its production, it varies in amplitude, configuration and latency at different recording sites and at the same sites on repeated trials. It reverses polarity deep in the cortex to become a large, negative wave deep in layer V, and maintains that polarity into the white matter. Current source density analysis reveals a strong sink in layer V, with a strong source just superficial to that sink and a weaker source in layer VI. The antidromic response disappears during spreading depression, but recovers more rapidly than the primary response evoked by skin stimulation. It decreases progressively in amplitude with continuous 200-Hz iterative stimulation, and recovers slowly at the end of stimulation. The primary response evoked by contralateral forepaw and hindpaw stimulation is highly localized, being entirely within the antidromic response distribution. The antidromic response in laboratory rats consists of a small, surface-positive component analogous to the pure antidromic response of cats, and of a large, surface-positive response analogous to that found in woodchucks, rabbits, opossums and slow lorises. It is argued that this latter response results from synaptic action in pyramidal tract axon collaterals, probably onto cells in layer V, rather than being a purely antidromic event.