Distribution of orexin neurons in the adult rat brain

Orexin (ORX)-A and -B are recently identified neuropeptides, which are specifically localized in neurons within and around the lateral hypothalamic area (LHA) and dorsomedial hypothalamic nucleus (DMH), the regions classically implicated in feeding behavior. Here, we report a further study of the distribution of ORX-containing neurons in the adult rat brain to provide a general overview of the ORX neuronal system. Immunohistochemical study using anti-ORX antiserum showed ORX-immunoreactive (ir) neurons specifically localized within the hypothalamus, including the perifornical nucleus, LHA, DMH, and posterior hypothalamic area. ORX-ir axons and their varicose terminals showed a widespread distribution throughout the adult rat brain. ORX-ir nerve terminals were observed throughout the hypothalamus, including the arcuate nucleus and paraventricular hypothalamic nucleus, regions implicated in the regulation of feeding behavior. We also observed strong staining of ORX-ir varicose terminals in areas outside the hypothalamus, including the cerebral cortex, medial groups of the thalamus, circumventricular organs (subfornical organ and area postrema), limbic system (hippocampus, amygdala, and indusium griseum), and brain stem (locus coeruleus and raphe nuclei). These results indicate that the ORX system provides a link between the hypothalamus and other brain regions, and that ORX-containing LHA and DMH neurons play important roles in integrating the complex physiology underlying feeding behavior.

High incidence of microscopic gastrointestinal stromal tumors in the stomach

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms with an annual incidence of approximately 10 to 20 per 1 million cases. Although pathologists have often observed incidental small GISTs in the stomach resected from patients with gastric cancer, no report on the real incidence of gastric GISTs is available. In this study, 100 whole stomachs resected from patients with gastric cancer were sectioned at 5-mm intervals and hematoxylin and eosin-stained slides (a mean of 130 slides for each case) were examined for microscopic GISTs. KIT (CD117), CD34, and desmin expression of the incidental tumors was evaluated by immunohistochemistry, and genomic DNA extracted from formalin-fixed and paraffin-embedded tumor tissues was analyzed for c-kit gene mutations in exon 11. In 35 of the 100 whole stomachs, we found 50 microscopic GISTs, all of which were positive for KIT and/or CD34 and negative for desmin. Most microscopic GISTs (45/50, 90%) were located in the upper stomach. Two of the 25 (8%) microscopic GISTs had c-kit gene mutations. Fifty-one leiomyomas with positive expression for desmin were observed in 28 of the 100 stomachs. Both leiomyomas and GISTs were found in 12 stomachs. These results indicate that microscopic GISTs are common in the upper portion of the stomach. Considering the annual incidence of clinical GISTs, only few microscopic GISTs may grow into a clinical size with malignant potential. Further studies are required to clarify the genetic events responsible for the transformation of microscopic GISTs to clinical GISTs.

Transgenic mice expressing a B cell growth and differentiation factor gene (interleukin 5) develop eosinophilia and autoantibody production

Interleukin 5 (IL-5) has been suggested to be involved in the growth and differentiation of B cells and eosinophils. Especially, Ly-1+ B cells, which have been considered to produce autoantibodies, are selectively developed by this lymphokine in long-term bone marrow culture. To envisage the possible engagement of IL-5 in the development of these cells in vivo, transgenic mice carrying the mouse IL-5 gene ligated with a metallothionein promoter were generated. Transgenic mice carrying the IL-5 gene exhibited elevated levels of IL-5 in the serum and an increase in the levels of serum IgM and IgA. A massive eosinophilia in peripheral blood, bone marrow, and spleen, and an infiltration of muscle and liver with eosinophils, were observed. When cadmium-containing saline was injected intraperitoneally into transgenic mice, IL-5 production was augmented about five times within 24 h, and a distinctive Ly-1+ B cell population became apparent in the spleen after 5 d. IL-5 receptors were detected on those cells by monoclonal antibodies against IL-5 receptors. Another interesting finding in these transgenic mice was an increase in polyreactive anti-DNA antibodies of IgM class. It is suggested, therefore, that aberrant expression of the IL-5 gene may induce accumulation of Ly-1+ B cells and eosinophils. Furthermore, this IL-5 transgenic mouse can be a model mouse for eosinophilia, and we can determine the role of IL-5 in the differentiation of Ly-1+ B cells and eosinophils by using this mouse.

Brainstem projections from the lateral hypothalamic area in the rat, as studied with autoradiography

Descending projections from the lateral hypothalamic area to the brainstem were studied, using [3H]-amino acid autoradiography, in the rat. Two main ipsilateral paths were reorganized. One is the periventricular fiber system projecting to the midbrain central gray. The other is a fiber system which eventually descends the central tegmental field, projecting strongly to the dorsal raphe nucleus, medial and lateral parabrachial nuclei, nucleus reticularis parvocellularis, solitary nuclei and dorsal motor nucleus of the vagus nerve. Sparse projections were observed to the nuclei raphe magnus, obscurus and pallidus, group B3 (or the ventrolateral subpial group) and spinal trigeminal nucleus.

Anatomical organization of the spinocerebellar system in the cat, as studied by retrograde transport of horseradish peroxidase

The distribution of spinocerebellar tract (SCT) neurons has been studied in the entire length of the spinal cord of the cat following injections of horseradish peroxidase into the cerebellum, and whether or not the axons of the labeled neurons crossed within the spinal cord was determined in cases with injections preceded by hemisections at the cervical levels. The SCTs were classified into the following crossed and uncrossed tracts according to the cell origin and the fiber course; the crossed SCTs originate from (1) the central cervical nucleus (the CCN-SCT), (2) lamina VIII neurons of the cervical to the lumbar cord (the lamina VIII-SCT), (3) spinal border cells (the border cell-SCT), (4) neurons in the medial lamina VII of the lumbar to the caudal spinal segments (the medial lamina VII-SCT), (5) ventral horn neurons (laminae VII and VIII) of the sacral and caudal segments (the ventral horn-SCT) and (6) dorsal horn neurons (lamina V) of the sacral and the caudal segments (the dorsal horn-SCT). The uncrossed tracts originate from (1) neurons of the medial lamina VI of C2 to T1 (the medial lamina VI-SCT of the cervical cord), (2) neurons in the central part of lamina VII of C6 to T1 (the central lamina VII-SCT of the cervical enlargement), (3) lamina V neurons of the lower cervical to the lumbar cord (the lamina V-SCT), (4) Clarke's column (the Clarke's column-SCT and (5) neurons in the medial lamina VI of L5 and L6 (the medial lamina VI-SCT of the lumbar cord). The present study suggests that the spinocerebellar system originates from more diverse laminae than has previously been known, and further refined studies on the topographic projections of each tract will yield more important and valuable information in this field.

Phase II feasibility study of preoperative chemotherapy with docetaxel, cisplatin, and fluorouracil for esophageal squamous cell carcinoma

The combination of docetaxel, cisplatin, and 5-fluorouracil (DCF) as preoperative treatment for esophageal squamous cell carcinoma (ESCC) has not been investigated. We carried out a multicenter phase II feasibility study of preoperative chemotherapy with DCF for ESCC. Patients with clinical stage II/III ESCC (International Union Against Cancer TNM classification system, 6th edition) were eligible. Chemotherapy consisted of i.v. docetaxel (70-75 mg/m(2)) and cisplatin (70-75 mg/m(2)) on day 1, and continuous infusion of fluorouracil (750 mg/m(2)/day) on days 1-5. Antibiotic prophylaxis on days 5-15 was mandatory. This regimen was repeated every 3 weeks with a maximum of three cycles allowed. After completion of chemotherapy, esophagectomy with extended lymphadenectomy was carried out. The primary endpoint was the completion rate of protocol treatment. Forty-two eligible patients were enrolled. During chemotherapy, the most common grade 3 or 4 toxicities were neutropenia (83%), anorexia (7%), and stomatitis (5%). Forty-one (98%) patients underwent surgery. The completion rate of protocol treatment was 90.5% (38/42). No treatment-related death was observed and the incidence of operative morbidity was tolerable. According to RECIST, the overall response rate after the completion of DCF was 64.3%. Pathological complete response was achieved in 17%. The estimated 2-year progression-free survival and overall survival were 74.5% and 88.0%, respectively. Although these data are preliminary, preoperative DCF was well tolerated. Antitumor activity was highly promising and warrants further investigation. This trial was registered with University Hospital Medical Information Network (no. UMIN000002396).

Difference in distribution of central terminals between visceral and somatic unmyelinated (C) primary afferent fibers

1. In the guinea pig, the central projections of somatic and visceral C-afferent fibers were compared by tracing arborizations labeled through injection of Phaseolus vulgaris leucoagglutinin (PHA-L) intracellularly into single neurons of the 13th thoracic dorsal root ganglia (DRG). 2. Two of 27 somatic C-afferent neurons that responded to electrical stimulation of the 13th thoracic (subcostal) nerve (conduction velocity: 0.69 +/- 0.14 m/s, mean +/- SD) were well enough marked to allow delineation of their central processes. In both cases, the entering axon ran rostrally, giving off branches that converged on a single terminal field located in the substantia gelatinosa (lamina II) with some extension in lamina I. The terminal field in each case extended approximately 400 microns rostrocaudally and 100 microns mediolaterally. 3. Intracellular recordings were obtained from 31 afferent units that responded to electrical stimulation of the celiac ganglion. Units with onset latencies of greater than 15 ms were classified as having visceral C-afferent fibers because the shortest course from the celiac ganglion stimulation electrodes to the DRG was greater than 7 mm (i.e., a conduction velocity of less than 0.5 m/s). 4. Seven visceral C-afferent fibers were labeled well enough to follow their central trajectories. Each had a main ascending and a descending central branch. Each main branch in turn issued several collaterals that terminated in the superficial dorsal horn (laminae I and II), laminae IV, V, and X, and occasionally in the dorsal and lateral funiculi. A few collaterals reached the contralateral laminae V and X.(ABSTRACT TRUNCATED AT 250 WORDS)

Establishment of methylation-sensitive-representational difference analysis and isolation of hypo- and hypermethylated genomic fragments in mouse liver tumors

Methylation of CpG sites in the genome, which is generally conserved during cell replication, is considered to play important roles in cell differentiation and carcinogenesis. However, investigations on changes in methylation status have been limited to known genes. To make a genome-wide search for differentially methylated genes, we developed a methylation-sensitive-representational difference analysis (MS-RDA) method. The representation of the genome was prepared using the methylation-sensitive restriction enzyme HpaII, and the mixture ratio of tester and driver DNAs was optimized to detect differences in methylation status of a single copy per diploid mammalian genome. By performing comparative MS-RDA of one hepatocellular carcinoma and of background liver tissue of one mouse treated with a food carcinogen (2-amino-3,4-dimethylimidazo[4,5-f] quinoline), we were able to identify (i) extensive hypomethylation of long interspersed nuclear element repetitive sequences in a number of hepatocellular carcinomas, (ii) reduction of the gene dosage of their mitochondrial DNA, and (iii) a hypermethylated DNA fragment of unknown origin. Furthermore, by adding the clones obtained in the first MS-RDA to the driver DNA [MS-RDA with elimination of excessive clones (MS-RDA-WEEC)], nine DNA fragments that could not be detected at the first MS-RDA were isolated as differentially methylated DNA fragments. MS-RDA, combined with MS-RDA-WEEC, is thus a promising approach to identify DNA fragments differentially methylated in two DNA sources.

Cells of origin of the spinocerebellar tract in the rat, studied with the method of retrograde transport of horseradish peroxidase

Following injections of horseradish peroxidase into the cerebellum, the distribution of labeled neurons was studied in the whole length of the spinal cord of the rat. To find the ascending side of the axons, injections were made following hemisections at C1 or between C1 and C2. Labeled spinocerebellar tract neurons were classified into two groups according to the axonal course in the spinal cord; one is composed of neurons with uncrossed ascending axons and the other, neurons with crossed ascending axons. Neurons of origin of the uncrossed tracts were located in the medial part of lamina VI of C2 to C8, the central part of lamina VII of C4 to C8, lamina V of C7 to L3 and Clarke's column. Neurons of origin of the crossed tracts were found in the central cervical nucleus of C1 to C3, the intermediate zone and the ventral horn of the lower thoracic and the lumbar segments (T11 to L3), and in the dorsal horn, the medial part of lamina VII and the ventrolateral part of the ventral horn of the sacral and caudal spinal cord. In comparison with our previous results in the cat, it was suggested that the spinocerebellar system in the rat is organized in the same fashion as in the cat, in terms of the location and the intraspinal axonal course of the cells of origin.

Descending input from the hypothalamic paraventricular nucleus to sympathetic preganglionic neurons in the rat

The descending projection of the hypothalamic paraventricular nucleus (PVN) to the sympathetic preganglionic neurons (SPNs) in the upper thoracic cord of the rat was studied. PVN-fibers were labeled by anterograde transport of Phaseolus vulgaris leucoagglutinin (PHA-L), while SPNs were retrogradely labeled with cholera toxin subunit B (CTb) which was injected into the superior cervical ganglion. SPNs labeled with CTb were mainly observed in the nucleus intermediolateralis (IML) pars principalis and pars funicularis, and a small number of them were in the nucleus intercalatus (IC) and central autonomic nucleus (CA). SPNs found in the IML had dendrites that projected in various directions. Five types of dendritic projections were noted: medial, rostral, caudal, lateral (including dorsolateral) and ventral. Longitudinal dendritic bundles interconnected each cell cluster in the IML. Medial dendrites of the IML, together with dendrites of the IC and CA, formed transverse dendritic bundles extending from the IML to the central canal. The transverse dendritic bundles disentangled near the midline and formed a loose dendritic plexus in the region just dorsal to the central canal. PVN-fibers labeled with PHA-L were observed primarily in lamina I and intermediate gray (lamina VII). Although varicose PVN-fibers and SPNs coexisted in the IML, the tight packing of the dendritic bundles prevented any clear demonstration of direct contacts between them. On the other hand, PVN-fibers were occasionally found to appose and wind around the primary or secondary dendrites of some SPNs of the CA and IC. These dendrites were studied with varicosities of PVN-fibers for a short length, and terminal boutons of PVN-fibers were also seen to make contact directly with the dendrities. The results of this study substantiated a direct connection between the PVN and SPNs, using a combination of immunohistochemical techniques for PHA-L and CTb. The possible involvement of a direct pathway from the PVN to SPNs in cardiovascular regulation is discussed.

Identification and distribution of the spinal and hypophyseal projection neurons in the paraventricular nucleus of the rat. A light and electron microscopic study with the horseradish peroxidase method

The distribution of labeled neurons in the paraventricular nucleus of the hypothalamus (PVN) was studied following injections of horseradish peroxidase (HRP) into the spinal cord (C8 to T1) or the hypophysis in the rat. Injections were also made in the spinal cord in another group of animals, which were subjected to water deprivation for a period of 3 days, and the PVN of these animals was examined with the electron microscope. Spinal projection neurons (paraventriculospinal tract, PVST, neurons) formed two groups; the dorsal and the ventral groups. They were located within the parvocellular part of the PVN and fused into one at the caudal level. The neurons of the dorsal group were well assembled whereas those of the ventral group were intermingled with paraventriculohypophyseal tract (PVHT) neurons, which were concentrated in the magnocellular part. Electron microscopic observations revealed that HRP-labeled neurons after spinal injections did not contain neurosecretory granules and that they were not affected by water deprivation. On the other hand, neurons containing a number of neurosecretory granules displayed a significant degree of dilatation of the endoplasmic reticulum as the result of water deprivation. These neurons contained no HRP granules. The present findings suggest that the PVST neurons are distinct from the PVHT neurons and that the neuronal groups of both systems form different cell columns within the nucleus.

The distribution of spinal projection neurons in the hypothalamus of the rat, studied with the HRP method

The distribution and number of hypothalamospinal tract (HST) neurons were studied following injections of horseradish peroxidase (HRP) at various levels of the rat spinal cord. The hypothalamus was divided into four areas and one nucleus, that is, the dorsal (DHA), posterior (PHA), medial (MHA) and lateral (LHA) hypothalamic areas and the paraventricular nucleus (PVN). The total numbers of HST neurons labeled with HRP varied according to the injection levels: 6,160 (C2 injections), 3,808 (T8), 1,961 (L1), 919 (L7) and 13 (S4). With C2 injections LHA contained 3,464 neurons, which accounted for 56% of the full number of HST neurons; similarly, PVN, 1,114 (18%); MHA, 865 (14%); DHA and PHA, 817 (12%). With L7 injections, LHA contained 444 labeled neurons, which accounted for 48% of the total; PVN, 327 (36%); MHA, 71 (8%); DHA with PHA, 77 (8%). As for the rostrocaudal distribution of labeled neurons, there was only a slight difference between the C2 and L6 injections in LHA, but no difference was noticed in PVN, DHA nor PHA. The present findings suggest that 70% of HST neurons may project to the cervical and thoracic cords. Although the number of labeled HST neurons decreased as the injection sites were placed caudally, no clearcut topographical arrangement was recognized in terms of the spinal projection levels.

The location of spinal neurons with long descending axons (long descending propriospinal tract neurons) in the cat: a study with the horseradish peroxidase technique

The distribution spinal neurons with long descending axons was studied in the cat by means of retrograde transport of horseradish peroxidase. Labeled neurons appeared bilaterally in the cervical and the thoracic cord following injections in the lumbosacral cord. In some cases hemisections were made rostrally and contralaterally to the injections in an attempt to determine whether or not the axons crossed. Neurons with uncrossed descending axons were located in laminae I, V, VII and VIII. Lamina I neurons were present in all the spinal segments. In lamina V labeled neurons were distributed mainly laterally in the cervical cord but medially and laterally in the thoracic cord. In the upper cervical and the thoracic cord laminae VII and VIII neurons were distributed very densely along the lateral cord, accounting for 30 and 40 of the total labeled neurons, respectively. In the cervical enlargement they were located in the middle part of lamina VII and in lamina VIII, accounting for about 25% of the total labeled neurons. Neurons with crossed descending axons were found in laminae V, VII and VIII, in the medial part of lamina VII including the intermediomedial nucleus of the thoracic levels and close to the central canal. Lamina V neurons were very small in number. The largest collections of labeled neurons were present in the medial part of laminae VII and VIII. They accounted for about 45% to 55% and 37% of the total in the cervical and the thoracic cord. These neurons may function as the long spinal reflex paths for forelimb-hindlimb synergies and the intercalated paths between the supraspinal descending tracts and the spinal motor centers.

Acquisition of certain streptomycin-resistant (str) mutations enhances antibiotic production in bacteria

Physiological differentiation (including antibiotic production) in microorganisms usually starts when cells encounter adverse environmental conditions and is frequently accompanied by an increase in the accumulation of intracellular ppGpp. We have found that the acquisition of certain streptomycin-resistant (str) mutations enables cells to overproduce antibiotics, demonstrating an increase in productivity 5- to 50-fold greater than that of wild-type strains. The frequency of such antibiotic-overproducing strains among the str mutants was shown to range from 3 to 46%, as examined with several strains of the genera Streptomyces, Bacillus, and Pseudomonas. Analysis of str mutants from Bacillus subtilis Marburg 168 revealed that a point mutation occurred within the rpsL gene, which encodes the ribosomal protein S12, changing Lys-56 (corresponding to Lys-43 in Escherichia coli) to Asn, Arg, Thr, or Gln. Antibiotic productivity increased in a hierarchical manner depending upon which amino acid residue replaced Lys at this position. The strA1 mutation, a genetic marker frequently used for mapping, had no effect on antibiotic productivity even though it was found to result in an amino acid alteration of Lys-56 to Ile. Gene replacement experiments with the str alleles demonstrated unambiguously that the str mutation is responsible for the antibiotic overproductivity observed. These results offer a rational approach for improving the production of antibiotic (secondary metabolism) from microorganisms.

Successful en bloc resection of a large superficial gastric cancer by using sodium hyaluronate and electrocautery incision forceps

BACKGROUND

The advisability of endoscopic mucosal resection (EMR) for treatment of large superficial gastric cancers has been challenged. For more reliable en bloc resection, a new method of EMR was developed that uses a viscous substance, sodium hyaluronate, and two newly designed devices.

METHODS

A large superficial gastric cancer was treated with this new EMR technique. Sodium hyaluronate was injected into the submucosa and mucosal incisions were made with a needle-knife. The newly developed incision forceps and flat-ended transparent hood were used for submucosal incisions.

RESULTS

The large cancer was successfully resected endoscopically as a single piece of mucosa 6 cm in diameter without complication. Histopathologic evaluation of the specimen confirmed that the resection was curative.

CONCLUSIONS

EMR with sodium hyaluronate along with two new devices may be a reliable method for en bloc resection of large superficial gastric lesions.

Descending projections from the spinal and mesencephalic nuclei of the trigeminal nerve to the spinal cord in the cat. A study with the horseradish peroxidase technique

Descending projections from the spinal (Vsp) and the mesencephalic nuclei (Vme) of the trigeminal nerve to the spinal cord were studied by means of the retrograde horseradish peroxidase technique in the cat. The number of labeled neurons was largest in the case of high cervical injections and decreased as the injections were placed caudally. Small laminae III and IV neurons of the nucleus caudalis (Vc) were labeled ipsilaterally following injections placed as caudally as the middle cervical segments (C4-C5). Lamina I (marginal) neurons of the Vc were labeled ipsilaterally after injections at the middle thoracic level (T6) but those of C1 were labeled after lumbar injections (L3). Lamina V neurons of C1 and the medullary counterparts were labeled bilaterally after injections placed caudally to thoracic segments. A few small neurons were labeled in the ipsilateral nucleus interpolaris (Vi) after injections placed as caudally as the middle cervical segments (C6). Among the subdivisions of the Vsp, the labeled neurons were most numerous in the nucleus oralis (Vo). They were medium-sized and large, and appeared bilaterally, with an ipsilateral predominance at the level of the superior olive. The great majority projected to the cervical segments but a few also projected to the lower cervical to the thoracic segments (C8-T9). Neurons of the Vme projected ipsilaterally to the upper cervical segments (C1-C3). No projections were found from the principal sensory nucleus. The present study suggests that the trigeminospinal projections of the Vsp and the Vme are composed of various cells of origin and thereby subserve not only the trigeminospinal reflex but other unknown functions.

Laparoscopic intragastric stapled resection of gastric submucosal tumors located near the esophagogastric junction

BACKGROUND

Laparoscopic resection cannot be applied easily to tumors located near the esophagogastric junction or the pyloric ring. We evaluated our laparoscopic intragastric surgical technique for gastric submucosal tumors located near the esophagogastric junction and the results of a clinical study.

MATERIALS AND METHODS

We performed our technique in six patients: one man and five woman with a mean age of 61 years. Using the laparoscopic procedure, after inflation of the stomach, we inserted two or three balloon-type ports into the stomach through the abdominal wall.

RESULTS

A stapled resection of gastric submucosal tumors using a laparoscopic linear stapler was performed successfully in all the patients. Without exception, stapled resections were successfully performed. The mean operation time was 168 min, and the blood loss was minimal There were no intra- or postoperative complications. The mean postoperative hospital stay was 9.8 days. The mean maximal diameter size of the resected specimens was 2.4 cm. Histopathologic diagnoses were gastrointestinal stromal tumors in five cases and enterogenous cyst in one. There were no recurrences during a mean follow-up period of 27 +/- 11.6 months.

CONCLUSION

Although we need to evaluate the long-term outcomes, our procedure is considered technically feasible, safe, and useful for the resection of gastric submucosal tumors located near the esophagogastric junction.

Treatment of patients with peritoneal metastases from gastric cancer

Despite recent advances in chemotherapy, outcomes of patients with peritoneal metastases (PM) from gastric cancer are still very poor and standard treatment has not been established. Although oral S‐1 appears to be effective for patients with PM, the effects of systemic chemotherapy are limited. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) yield fewer benefits in patients with PM from gastric cancer than in patients with PM from other malignancies. In comparison, repeated intraperitoneal chemotherapy (RIPEC) with taxanes using an implantable peritoneal access port has a pharmacokinetic advantage for the control of peritoneal lesions and in combination with systemic chemotherapy can result in surprisingly long‐term survival in patients with PM from gastric cancer. Herein, we review the results of recent clinical studies specifically targeting PM from gastric cancer and discuss future prospects for an intraperitoneal approach to the ideal treatment of patients with gastric cancer with peritoneal involvement.

The lethal effect of a benzamide derivative, 3-methoxybenzamide, can be suppressed by mutations within a cell division gene, ftsZ, in Bacillus subtilis

3-Methoxybenzamide (3-MBA), which is known to be an inhibitor of ADP-ribosyltransferase, inhibits cell division in Bacillus subtilis, leading to filamentation and eventually lysis of cells. Our genetic analysis of 3-MBA-resistant mutants indicated that the primary target of the drug is the cell division system involving FtsZ function during both vegetative growth and sporulation.

Altered expression of several genes in highly metastatic subpopulations of a human pulmonary adenocarcinoma cell line

Non-small cell lung cancer is associated with approximately 85% mortality due to its high metastatic potential. Therapeutic efforts have failed to produce a significant improvement in prognosis. In this situation, a better understanding of the key factors of metastasis may be useful for designing new molecular targets of therapy. In order to identify these factors, we compared the expression profiles of two subpopulations of an adenocarcinoma cell line with a high metastatic potential, PC9/f9 and PC9/f14, with the parent cell line, PC9, using a cDNA array. The expression of 15 genes was found to be significantly enhanced or reduced in the highly metastatic subpopulations. The expression of matrix metalloproteinase-2 (MMP-2), plasminogen activator inhibitor-1 (PAI-1) and interleukin-1 (IL-1 alpha) were upregulated in the highly metastatic subpopulations, while the expression of carcinoembryonic antigen (CEA), caspase-5, Fas ligand, Prk/FNK, cyclin E, cyclin B1, Ki-67, proliferating cell nuclear antigen (PCNA), Smad4, macrophage proinflammatory human chemokine-3 alpha (MIP-3 alpha)/LARC, Met and CD44 were downregulated. Data from the literature suggest that the altered expression of MMP-2, PAI-1, IL-1 alpha, CEA, caspase-5, Fas ligand, Prk/FNK and Smad4 promotes the highly metastatic phenotype. The differential expression of these genes was confirmed by Northern blot analysis, standard reverse transcription-polymerase chain reaction (RT-PCR) and real-time quantitative RT-PCR. This analysis in subpopulations of a lung cancer cell line indicated that the highly metastatic potential of lung cancer may be induced not by an alteration in the expression of a single gene, but by the accumulation of alterations in the expression of several genes involved in extracellular matrix (ECM) adhesion disruption, ECM degradation, escape from apoptosis, and resistance to transforming growth factor-beta(1) (TGF-beta(1)). Strategies for inhibiting metastasis of pulmonary adenocarcinoma should be designed accordingly.

A direct hypothalamic projection to the superior salivatory nucleus neurons in the rat. A study using anterograde autoradiographic and retrograde HRP methods

The location of the superior salivatory nucleus and terminal labelings of the hypothalamic descending fibers were demonstrated in the nucleus reticularis parvocellularis using HRP and the autoradiographic techniques, respectively. When both techniques were used in the same animals, some HRP-labeled neurons were seen among the accumulations of silver grains, suggesting pericellular terminations. The present study demonstrates that the hypothalamic efferents project directly to the superior salivatory nucleus innervating salivary and lacrimal glands.

A neural cell-type-specific expression system using recombinant adenovirus vectors

We demonstrated neural cell-type-specific gene expression using an adenovirus vector, which is useful for delivering foreign genes into quiescent neural cells. We produced eight recombinant replication-defective adenoviruses carrying the lacZ reporter gene driven by various promoters, including those of the L7/PCP2 gene (highly restricted expression in cerebellar Purkinje cells), and the myelin basic protein (in oligodendrocytes) gene. We demonstrated in vitro and in vivo promoter-driven, neural cell-type-specific gene expression by recombinant adenoviruses. The genes were transferred into these recombinant adenoviruses and expressed with high levels of efficiency in vitro and in vivo. In primary culture, the recombinant adenoviruses AdexL7-NL-LacZ and AdexMBP-NL-LacZ appeared to be expressed in a Purkinje cell and oligodendrocyte-specific manner. Introduction of 10(8) pfu of these viruses into the adult rat cerebellum by stereotactic injection yielded neural cell-type-specific expression without apparent toxicity to the animals. Thus, adenovirus vectors are useful for cell-type-specific therapeutic uses and in studies requiring neural cell-type-specific gene expression.

Dualistic behavior of ATP-sensitive K+ channels toward intracellular nucleoside diphosphates

ATP-sensitive K+ (KATP) channels are intracellular ligand-gated channels which regulate diverse cellular functions. Intracellular nucleoside diphosphates (NDPs) are essential for the physiological opening of KATP channels which would otherwise be permanently closed by their overt sensitivity to intracellular ATP. We find that KATP channels exhibit dualistic behavior toward NDPs depending on their operative condition. When channels are in the spontaneous operative condition, NDPs antagonize channel inhibition by intracellular ATP. When channels have "run down", NDPs induce channel opening but no longer antagonize intracellular ATP. The switch of the KATP channel response to the same ligand, i.e., NDPs, is controlled by a Mg-ATP-dependent reaction. The condition of the target protein therefore determines the effect of the ligand. This property provides a novel basis to evaluate the dynamic regulation of ion channels by their ligands.

The location of spinal projection neurons in the cerebellar nuclei (cerebellospinal tract neurons) of the cat. A study with the horseradish peroxidase technique

The distribution of spinal projection neurons was studied in the cerebellar nuclei of the cat following injections of horseradish peroxidase (HRP) into the cervical, thoracic and lumbar cord. HRP-positive (labeled) neurons were found in the medial (fastigial) and the posterior interpositus nuclei on the side contralateral to the cervical injection, being most numberous in cases with injections between the C2 and the C3 segments. In the medial nucleus (M) labeled neurons were distributed in the central to the caudal portions, and there was a conspicuous group of labeled small neurons extending from the ventrolateral part to the intermediate zone between the M and the anterior interpositus nucleus. With an increasing number of medium-sized neurons, this neuronal group persisted caudally in a similar position, ventromedial to the posterior interpositus nucleus (IP). Labeled large neurons were seen in the medial third of the IP. In the two cases labeled neurons of medium and small sizes were equal in number, and the neurons of the IP constituted about 10% of the total number of the spinal projection neurons. The present study suggests that the neurons of the M and the IP, including those of the intermediate group located between the two, project the bulk of the crossed descending fibers as far caudally as the C2 and the C3 segments.

The localization of the site of arylalkylamine N-acetyltransferase circadian expression in the photoreceptor cells of mammalian retina

To investigate the molecular mechanism of the melatonin rhythm in the mammalian retina, we examined the temporal mRNA expression pattern of arylalkylamine (serotonin) N-acetyltransferase (AA-NAT), the rate-limiting enzyme in melatonin synthesis in the rat retina. Rat AA-NAT mRNA was detected exclusively in the retinal photoreceptors in the outer nuclear layer--low during the day and increased more than threefold at night. The nocturnal AA-NAT expression in rat retina was also confirmed by RNase protection and the AA-NAT enzymatic activity. This is the first report to localize the site of AA-NAT mRNA circadian expression in mammalian photoreceptor cells.