Observations of Breinlia booliati in a new host, Rattus rattus jalorensis, from Kuantan, state of Pahang, Malaysia.

Breinlia booliati Singh and Ho, 1973 is described from the Malaysian wood rat, Rattus rattus jalorensis Bonhote. The parasites presented here were originally discovered in 1955 in Kuantan, Malaysia, but were not classified until now. On the basis of morphological observations of anatomical structures and comparisons with other species of Breinlia, it was determined that the parasites were B. booliati. The parasites discussed here show slight deviation from B. booliati, but they do not warrant a new species classification. There is some variation in anatomical measurements, the number of male caudal papillae, and the morphology of the microfilariae. Breinlia booliati from a new host is described in this article, with a brief discussion on Rattus species that are hosts of B. booliati and vectors that transmit the parasite. The occurrence of B. booliati in R. r. jalorensis represents the first report of the parasite in this host.

Pressure, volume, and chemosensitivity in afferent innervation of urinary bladder in rats.

Bladder afferent nerve activity was recorded from the pelvic and hypogastric nerves of rats anesthetized with pentobarbital sodium. Bladder filling with isotonic NaCl at a rate of 250 microl/min excited multiunit afferent activity in the hypogastric nerve by 190 +/- 38% over background at a pressure of 30 mmHg, whereas 150 meq/l KCl at the same filling rate excited hypogastric nerve activity by 498 +/- 103% (P < 0.0001). This difference was localized to a group of chemosensitive fibers that are excited by bladder filling with KCl in a concentration-dependent fashion but are insensitive to bladder filling with NaCl. Bladder filling with 200 meq/l KCl at different filling rates caused a bursting pattern of discharge in these fibers at consistent bladder volumes but with a pressure threshold that increased proportionately with filling rate. Other hypogastric bladder afferent fibers were activated to a similar extent by NaCl and KCl solutions. Chemoreceptive bladder afferent fibers were rare in the pelvic nerve (1 of 15 units), and multiunit preparations showed comparable excitations during bladder filling with NaCl and KCl solutions. The bursting activation of bladder chemoreceptive afferent nerves in hypogastric nerves could signal noxious overdistension and/or inflammation of the bladder.

Conditional immortalization of neuronal cells from postmitotic cultures and adult CNS.

To determine whether postmitotic neurons can be immortalized by oncogenic transduction, we used two approaches involving conditional expression of a temperature-sensitive SV40 large T antigen (Tts). Initially, Tts was introduced into E17 rat embryonal hippocampal cells that were then cultured at the non-permissive temperature to enrich for postmitotic pyramidal neurons, and subsequently cloned at the permissive temperature. One clonal line (HMR10-3) expressed neuron-specific proteins upon differentiation, was capable of generating action potentials, and formed synapses with primary rat neurons in co-culture. Replating of these postmitotic cells at the permissive temperature resulted in reversible loss of neurofilament expression. Conditionally immortalized cell lines were also generated from the brain of an adult mouse carrying an inducible Tts transgene. These lines proliferated in a T antigen-dependent manner and expressed neuron-specific proteins upon differentiation at the non-permissive temperature. These results suggest that postmitotic neurons can be induced to enter the cell cycle without losing their commitment to a neuronal lineage.

Localization of immunoreactive epidermal growth factor receptor in neonatal and adult rat hippocampus.

The regional and developmental expression of epidermal growth factor (EGF) receptor in rat hippocampus was investigated utilizing immunocytochemical techniques at the light and electron microscopic levels. EGF receptor immunoreactivity in adult hippocampus was compared to that found at postnatal day 7 (P7). While the receptor was observed in P7 hippocampus, immunostaining was more prominent in the adult hippocampus, especially in the pyramidal CA2 field. Ultrastructural analysis of this region revealed that the receptor was localized to the cell bodies of both P7 and adult neurons rather than the axons or dendrites. The expression of EGF receptor in selected regions of the adult brain was verified by Western blotting. These results demonstrate the presence of EGF receptor in rat hippocampus as early as P7, localize the receptor to the pyramidal cell body, and establish the hippocampal formation, particularly CA2, as a major site of EGF receptor expression in rat brain.

Activation of mitogen-activated protein kinase by epidermal growth factor in hippocampal neurons and neuronal cell lines.

Epidermal growth factor (EGF) functions in a bimodal capacity in the nervous system, acting as a mitogen in neuronal stem cells and a neurotrophic factor in differentiated adult neurons. Thus, it is likely that EGF signal transduction, as well as receptor expression, differs among various cell types and possibly in the same cell type at different stages of development. We used hippocampal neuronal cell lines capable of terminal differentiation to investigate changes in EGF receptor expression, DNA synthesis, and stimulation of mitogen-activated protein (MAP) kinase by EGF before and after differentiation. H19-7, the line that was most representative of hippocampal neurons, was mitogenically responsive to EGF only before differentiation and increased in EGF binding after differentiation. MAP kinase was stimulated by EGF in both undifferentiated and differentiated cells, as well as in primary hippocampal cultures treated with either EGF or glutamate. These results indicate that the activation of MAP kinase by EGF is an early signaling event in both mitotic and postmitotic neuronal cells. Furthermore, these studies demonstrate the usefulness of hippocampal cell lines as a homogeneous neuronal system for studies of EGF signaling or other receptor signaling mechanisms in the brain.

Immortal rat hippocampal cell lines exhibit neuronal and glial lineages and neurotrophin gene expression.

Clonal cell lines of rat embryonic hippocampal origin have been developed by using retroviral transduction of temperature-sensitive simian virus 40 large tumor antigens. The cell lines undergo morphological differentiation at the nonpermissive temperature and in response to differentiating agents. Immunocytochemical analysis indicates that various lines are derived from progenitors of neuronal, glial, and bipotential lineages. Selected neuronal lines differentiate in response to diffusible factors released by primary glia, and one line of glial lineage supports the maturation of primary neurons in culture. Selected cell lines exhibit different patterns of neurotrophin gene expression that change after differentiation. In some lines, the relative levels of neurotrophin 3 and brain-derived neurotrophic factor message expression may reflect the developmental or regional differential expression seen for these genes in the hippocampus in situ. These hippocampal cell lines, which express markers indicative of commitment to neuronal or glial lineages, are valuable for studies of development and plasticity in these lineages, as well as for studies of the regulation of neural trophic interactions.

Diverticula of the female urethra: diagnosis by endovaginal and transperineal sonography.

Diverticula of the female urethra can be difficult to diagnose. Invasive contrast studies (voiding cystourethrography or double-balloon urethrography) or urethroscopy are frequently required for definitive diagnosis. Although transabdominal sonography has been able to visualize large diverticula, this technique has not proved useful in routine screening. In this study, we examined the use of higher frequency (5 MHz) near-focus endovaginal or transperineal sonography for the diagnosis of urethral diverticula. Five patients with radiographically proved (three with double-balloon urethrography and two with voiding cystourethrography) urethral diverticula were examined with endovaginal (two cases) or transperineal (four cases) sonography. In all five cases, sonography showed the diverticula previously demonstrated on the contrast study. The spatial relationship of the diverticula to the urethra, an important consideration at surgery, was shown more clearly by sonography than by contrast radiography. These findings suggest that sonography may be useful as a noninvasive screening technique for urethral diverticula.

Blunt trauma of uterovaginal and vesical prolapse with associated bladder rupture.

A 71-year-old woman had complete uterovaginal and vesical prolapse associated with a large decubitus ulcer on the anterior vaginal wall. She sustained blunt trauma to the perineum after a fall, which resulted in rupture of the prolapsed bladder. The management of this rare problem is discussed.

Mechanism of renin release in exercising dog.

Exercise is associated with an increase in plasma renin activity (PRA). The purpose of this study was to determine the role of the prostaglandin (PG) and adrenergic pathways in the renin release with exercise in the dog. One group of animals (n = 4) was exercised under control untreated and indomethacin- and meclofenamate- (2 mg/kg) treated conditions. A 155% increase in PRA was not influenced by PG inhibition. In a second group (n = 7) PRA was 1.22 +/- 0.32, 3.29 +/- 1.59, 6.28 +/- 2.85, and 5.30 +/- 2.00 ng ANG I X ml-1 X h-1 at rest and during light, moderate, and heavy exercise, respectively. Guanethidine treatment (15 mg/kg) decreased mean PRA by 41, 50, 70, and 73% at rest and during the three levels of exercise, respectively. In a third group (n = 5) control exercise runs were repeated after metoprolol treatment. Selective beta 1-blockade completely abolished the increment in PRA observed with exercise. These data demonstrate that the elevation of PRA during exercise in the dog is mediated by increased sympathetic nerve activity involving beta 1-receptors and that it is not dependent on alterations in PG synthesis.

The use of the systolic time interval for predicting left ventricular ejection fraction ischemic heart disease.

A large series of 306 patients with ischemic heart disease was studied with automated systolic time intervals and left ventricular ejection fraction as determined by the angiocardiographic method. It was found the pre-ejection period, left ventricular ejection time, delta values, and PEP/LVET ratio all were related to the ejection fraction. However, in all instances the correlation was too low and the scatter of the data was too large to warrant the use of the systolic time intervals for predicting left ventricular function as indicated by the ejection fraction.