Peripheral nerve injury induced expression of mRNA for serine protease inhibitor 3 in the rat facial and hypoglossal nuclei but not in the spinal cord.

The current work has documented the expression of the mRNAs for serine protease inhibitor 3 (SPI-3) in the facial and hypoglossal nuclei following peripheral nerve transection by using the in situ hybridization method. The signals appeared 6 hour after nerve injury; they became stronger on day 1 of injury and persisted for 21 days. SPI-3 may be involved during early events of modulating the activities of serine proteases following nerve injury. Such activities may include synaptic stripping and re-organization and facilitation of glial cell reaction to nerve injury. In the later stages of nerve injury SPI-3 may enhance neuronal survival, growth of neurites and re-establishment of synaptic contacts in the facial and hypoglossal nuclei. Hypoglossal but not facial nerve transection caused the expression of mRNAs for SPI-3 in the pineal gland. The signals appeared 6 hours after nerve injury and persisted for 21 days. The significance of this observation is not known but it indicates that the pineal gland senses injury to some peripheral nerves including the hypoglossal nerve. The study has also showed that axotomy of the sciatic nerve did not give rise to the up-regulation of the mRNAs for SPI-3 in the spinal cord. There was no hybridization signals in the lumbar segments; an indication that SPI-3 may not form part of molecules that are released during sciatic nerve transaction by the neural and non-neural cells of the spinal cord. At the moment there are no antibodies for SPI-3 and therefore future studies are needed to verify the findings. It will be interesting also to study on the role of pineal gland during peripheral nerve injuries.

Rare origin of supernumerary renal vessels supplying the lower pole of the left kidney.

The current observations have documented rare vascular anomalies in the right and left kidneys from a male and female cadaver, respectively. In the female left kidney in addition to being supplied by the normal renal artery and vein it contained a left lower polar renal artery and vein. The polar artery took origin from the inferior mesenteric artery to supply the lower pole and was drained by the left lower polar vein that opened into the left common iliac vein. The right kidney from a male cadaver showed supernumerary renal arteries and veins. The supernumerary upper renal artery took origin from the aorta and after a short course it gave rise into a cranial branch that took a long course to supply the lower pole and a caudal branch that entered the right kidney at the hilum. The supernumerary lower renal artery also took origin from the aorta and passed to supply the lower pole of the right kidney. Therefore, the lower pole of the right kidney received two arteries, but was not associated with a polar vein. The right kidney in addition to the normal right renal vein contained a supernumerary right renal vein. The vein was seen at the hilum and was the most posterior structure; passing behind the supernumerary lower renal artery to open into the posterior surface of the inferior vena cava. The anomalies described in the current observation present a unique pattern of congenital renal vascular abnormalities that may be of surgical importance.

The morphological features of major and accessory fissures observed in different lung specimens.

The current study reports the presence of accessory fissure and anomalies in the major fissure and lobation in both the right and left lungs. The results indicated that out 102 lung specimens observed in the dissection room 37.26% appeared to have fissural or lobation anomalies and 63% of the anomalies were described in the right lung. Fissural anomalies accounted for 28.44% while the lobation anomalies were observed in 8.82% of the specimens. The abnormal fissure that were observed included the left minor fissure 10.78%, incomplete horizontal fissure 7.84%, diaphragmatic fissure 7.84%, right minor fissure 0.98% and azygos fissure 0.98%. Further observation revealed that 5.88% of the right lungs appeared to have two lobes and 2.94% of the left lungs had three lobes. The current study indicates that the right lung is commonly affected with fissural and lobation anomalies and that the left minor fissure is the commonly occurring fissural anomaly. Documentation and familiarization of these anomalies remain to be important for making correct radiological diagnosis and also for proper surgical management of lung pathology.

Bifid liver presenting with anomalous quadrate and caudate lobes and a transverse gallbladder.

The current Observation reports multiple anomalies of the liver of a 55-year-old male cadaver. Observations revealed the presence of anomalies on the diaphragmatic and visceral surfaces of the liver. The diaphragmatic surface presented with a deep furrow that run obliquely from the fissure for the inferior vena cava to the inferior border of the liver. It divided the liver partially into the right and left segments that remained united by the liver tissue that measured about 0.7 cm thick. The two segments were easily pulled apart for up to 3 cm. A similar fissure did not appear on the visceral surface. The visceral surface presented with multiple anomalies that included a vertically oriented porta hepatis, abnormal Y-shaped fissures on the right lobe, transverse gallbladder, absence of the caudate process on the caudate lobe, abnormal quadrate lobe, and transverse fissure on the right lobe. The three fissures that formed a Y-shaped configuration delineated the quadrate lobe. The right and left arms of the Y-shaped fissure terminated in the porta hepatis. Congenital anomalies of the adult liver are rare; therefore continued documentation of such anomalies remains to be important in medical sciences and in the understanding of liver ontogeny.

Right azygos lobe occurring with fissural and lobation anomalies

Background: The azygos lobe is a rare anomaly of the lung that is separated from the rest of the upper lobe by an azygos fissure. The lobe is encountered mostly in the right lung but a few cases have also been described in the left lung. It occurs at a frequency of 0.25-1and has surgical and radiological importance. For example it can give rise to opacity on the X-ray that can mimic lung pathology.Observations: The azygos lobe was observed in the upper lobe of the right lung from a 45 years old male cadaver during dissection. The apex of the lung contained a vertical fissure that isolated medially the azygos lobe. The lobe appeared columnar in shape and it measured 4.7cm long and 3.7cm wide; its posterior border contained a notch. In addition to the azygos lobe the right lung also contained an incomplete horizontal fissure and therefore was divided by an oblique fissure into two lobes.Conclusion: The current observation has documented the co-existence of an azygos lobe with incomplete horizontal fissure and two lobes on the right lung. The findings have added knowledge on the morphology of the azygos lobe and have also raised awareness that it can occur with other fissural anomalies

Apocrine secretory mechanism: recent findings and unresolved problems.

Cell secretion is an important physiological process that ensures smooth metabolic activities, tissue repair and growth and immunological functions in the body. It occurs when the intracellular secretory materials are released to the exterior; these may be in the form of lipids, protein or mucous and may travel through a duct system or via blood to reach the target organ. To date three types of secretory mechanisms have been characterized, they include apocrine, holocrine and exocytosis. Apocrine secretion occurs when the release of secretory materials is accompanied with loss of part of cytoplasm. The secretory materials may be contained in the secretory vesicles or dissolved in the cytoplasm that is lost during secretion. In holocrine secretion, the entire cell is secreted into the glandular lumen, and it is presumed that the intended secretory materials are contained in the cell cytoplasm. Exocytosis is the most commonly occurring type of secretion; here the secretory materials are contained in the secretory vesicles and released without loss of cytoplasm. Apocrine secretory mechanisms have not been properly discussed; for example the biochemical and physiological pathways that regulate apocrine secretory process are not clearly known. Similarly, the plasma membrane dynamics during apocrine secretion has not been researched. In other glands morphological features during apocrine secretion have not been documented. The current paper reviews what is known about apocrine secretion, recent findings and highlights on the unresolved areas for future research.

Sexual differences and effects of castration on secretory mode and intracellular calcium ion dynamics of golden hamster Harderian gland.

The aim of the present work was to study the sexual differences in secretory mechanisms and intracellular calcium ion dynamics in the Harderian gland of the golden hamster. In both sexes the Harderian gland consisted of small and large lobes. In the intact control male glands the secretory portions of both lobes showed wide lumina that contained secretory material and cytoplasmic fragments, suggestive of the occurrence of exocytosis and apocrine secretion. After perfusion with HEPES-buffered Ringer's solution containing 10 microM carbamylcholine (CCh), the glandular cells showed features of enhanced secretion and a rise in intracellular calcium concentration ([Ca2+]i). In the intact control female gland the lumina of most secretory portions in the large lobe contained porphyrin accretions, and exocytosis was the sole secretory mechanism. Stimulation of the large lobe with 10 microM CCh did not raise [Ca2+]i or cause enhanced secretion. The small lobe in females resembled the male gland in secretory functions, and CCh administration caused enhanced secretion and a rise in [Ca2+]i. Castration in males abolished apocrine secretion; exocytosis became the sole secretory mechanism, and stimulation of the glandular cells with CCh did not cause enhanced secretion or induce a rise in [Ca2+]i. To the contrary, in females, castration restored apocrine secretion and CCh administration caused enhanced secretion and a rise in [Ca2+]i. Castration did not affect the secretory mechanisms and the effect of CCh on the glandular cells in the small lobes of both male and female glands. The present study points to the possibility that sex hormones may control the functioning or expression of muscarinic receptors in the Harderian gland of the golden hamster.

Morphological changes and expression of protein kinase CK2 beta subunit in the microglia after hypoglossal nerve transection.

Following hypoglossal nerve transection, the microglia of the rat hypoglossal nucleus expressed protein kinase CK2 beta subunit immunoreactivity. CK2 beta immunostaining occurred on the operated side from postoperative day 3; on day 5 we observed strong immunoreactivity and the immunopositive microglial cell processes surrounded the injured neurones. Thereafter, the immunoreactivity decreased gradually and on day 10 the immunopositive cells surrounded only a few injured neurones. Electron microscopic observations on the hypoglossal nucleus revealed microglia-neuronal contact within 3 hours of nerve injury, and by day 3 all the injured neurones were in contact with microglial cells. These observations indicated that microglia-neuronal contact occurred earlier than the CK2 beta subunit immunoreactivity. CK2 may not be implicated during the initial migration of the microglia to the injured neurones; however, it may enhance the growth and elongation of the microglial cell processes around the injured neurones.

Exocytosis in the antral gastrin cells of mouse, rat, and guinea pig after stimulation by carbamylcholine.

In order to capture the exocytotic figures of gastrin cells in the pyloric antrum of the stomach, we examined antral cells of the mouse, rat, and guinea pig by electron microscopy following stimulation with the cholinergic secretagogue carbamylcholine. Increased numbers of omega profiles indicative of exocytosis were seen in the basal or lateral cell membrane after stimulation with carbamylcholine. The number of exocytotic figures in stimulated gastrin cells was higher in the guinea pig than in the mouse and rat. Coated and non-coated omega profiles and coated pits in the plasma membrane were smaller than the secretory granules. Omega profiles with or without electron-dense contents were seen. Coated and non-coated vesicles were often visible near the plasma membrane of stimulated gastrin cells in all three species, large cytoplasmic vacuoles also being found in the guinea pig. In the mouse pretreated with horseradish peroxidase, reaction deposits were observed in the omega profiles and in microvesicles near the plasma membrane. These results suggest that, after exocytosis, membrane retrieval and endocytosis occur in the gastrin cells.

Secretagogue-induced apocrine secretion in the Harderian gland of the rat.

Harderian glands of male albino rats were stimulated with secretagogues and examined by transmission and scanning electron microscopy for the purpose of studying the apocrine secretory mechanism. Rats in the control group were perfused with standard HEPES-buffered Ringer's solution. Their glandular endpieces showed wide lumina that contained few secretory materials; spontaneous exocytosis was sometimes observed. However, there were no features suggestive of an apocrine secretory mechanism or myoepithelial cell contractions. After stimulation with NaF+AlCl3 or carbachol in HEPES-buffered Ringer's solution, the rats shed "bloody tears" and the glandular lumina were jammed with apical protrusions, cytoplasmic material and secretory products. The basal surface of the glandular cells showed bulging caused by myoepithelial cell contraction. Perfusion with HEPES-buffered Ringer's solution containing papaverine inhibited secretagogue-induced myoepithelial cell contraction but not the enhanced secretory activities of the glandular cells. The present results demonstrate that the Harderian gland of the rat can release secretory material not only by exocytosis, but also by an apocrine mechanism under stimulating conditions, and that myoepithelial cell contraction may not be involved in causing apical protrusion in the glandular cells.

Lipid secretory mechanisms in the mammalian harderian gland.

The mammalian Harderian glands are lipid-secreting glands. In an unstimulated condition, the glandular cells frequently exocytose the lipid materials; however, no intracellular calcium ion ([Ca2+]c) changes are detectable. Cholinergic (muscarinic) secretagogues induce secretory activity and increase of [Ca2+]c. A G-protein activator, sodium fluoride, enhances the secretory activity and increase of [Ca2+]c. Removal of extracellular calcium ions inhibits the secretion enhanced by cholinergic stimulation. Under pharmacologic stimulation, glandular cells may show an apocrine-like secretory pattern. Cholinergic stimulation also induces contraction of the myoepithelial cells covering glandular end pieces; however, the reduction in volume of glandular end pieces is not prominent. Catecholamines have no effect on the release of lipid materials. These results indicate the involvement of G-proteins linking with muscarinic receptors and Ca2+ dynamics (increase of [Ca2+]c and Ca2+ influx) in lipid secretion by glandular cells and in contraction of myoepithelial cells of mammalian Harderian glands. However, the increase of [Ca2+]c in Harderian glands was less when compared with other cells--for instance, those which secrete protein.

G-protein activation enhances Ca(2+)-dependent lipid secretion of the rat harderian gland.

We studied the secretory mechanism of the Harderian gland of rats. After perfusion with HEPES-buffered Ringer's solution containing NaF (10 mM) with AlCl3 (10 microM), a G-protein activator, the glandular cells of the Harderian gland showed massive exocytosis and apocrine-like protrusions on the luminal surface. Some of the secretory vacuoles aggregated within the cytoplasm, and large vacuoles were formed. Contraction of the myoepithelial cells covering the glandular endpieces caused a narrowing of the glandular lumina, which contained cytoplasmic fragments, and deformation of the basal contour of the glandular end-pieces. The basal regions of the glandular cells also bulged between the myoepithelial cells. Secretory vacuoles were also discharged to the lateral cell surface, and the intercellular spaces were dilated. The enhanced secretory activities of the glandular cells and the contraction of the myoepithelial cells were similar to those in rats stimulated with 10 microM carbachol (CCh). However, dilatation of the endoplasmic reticulum in glandular cells (type A cells), which leads to the formation of small vesicles, was observed in those glands stimulated by NaF+AlCl3, but not in those stimulated by CCh. Removal of Ca2+ from the perfusing HR or addition of EDTA (0.5 mM) diminished and inhibited NaF+AlCl3- or CCh-enhanced secretory activity of the glandular cells and also allayed the deformation of glandular cells caused by myoepithelial cell contraction. The present results demonstrate the involvement of G-proteins and Ca(2+)-influx in the lipid secretion of glandular cells and in the contraction of myoepithelial cells of the Harderian gland in rats.