Uncleaved env gp160 of human immunodeficiency virus type 1 is degraded within the Golgi apparatus but not lysosomes in COS-1 cells

The fate of newly synthesized human immunodeficiency virus type 1 env gp160 was examined in COS-1 cells. The results of morphological chase experiments involving cycloheximide demonstrated that gp160 was retained in the Golgi apparatus for longer than the half-life of the molecule. The degradation of gp160 was insensitive to both bafilomycin A1 and leupeptin (< 0.2 mM), which block lysosomal proteolysis. However, degradation was effectively suppressed by leupeptin at higher concentrations, maximally at 1.7 mM. Furthermore, undegraded gp160 was accumulated in the Golgi apparatus, but was not detected in lysosomes. These results indicate that in COS-1 cells gp160 is not degraded in lysosomes, but rather that degradation takes place in the Golgi apparatus.

High intraocular pressure-induced ischemia and reperfusion injury in the optic nerve and retina in rats

PURPOSE

The purpose of this paper is to describe the damage caused to the retina and the axons of the optic nerve by acute ischemia-reperfusion injury and the extent to which optic nerve damage correlates with the duration if ischemia due to high intraocular pressure (IOP).

METHODS

Acute ischemia in the retina and optic disc was induced in albino rats by increasing the IOP to 110 mmHg for a period of 45-120 min. Thereafter, the eyes were reperfused at normal IOP after 7 days. The retina and optic nerve were examined by light and electron microscopy, and morphometrical counts of the optic nerve axons were performed.

RESULTS

After 45 min of ischemia, electron microscopic examination revealed swelling of mitochondria and degeneration of neurotubules on axons in cross sections of the optic nerve. The axonal counts in eyes subjected to 45 min of ischemia were 29% lower than in control eyes. After 60 min of ischemia, there were distinct disruptions of mitochondria and degeneration of the axons. After 90 min of ischemia, numerous axons showed degeneration with disordered myelin sheaths. Neuronal cell death was seen in the retina, mainly in the ganglion cell layer.

CONCLUSION

Damage to the retinal ganglion cell layer and the optic nerve was evident after only 45 min of ischemia in normal eyes. This experiment suggests that seriously injured eyes must be protected from high IOP; if IOP elevation is required during vitrectomy, it is essential to reduce the duration of interruption of blood flow to a minimum.

Development and pharmacokinetics of galactosylated poly-L-glutamic acid as a biodegradable carrier for liver-specific drug delivery

PURPOSE

A biodegradable carrier for the liver-specific delivery of drugs was developed using poly-L-glutamic acid (PLGA) modified with galactose (galactosylated PLGA or Gal-PLGA), and its feasibility was investigated in mice.

METHODS

111In-PLGA and 111In-Gal-PLGAs were injected in mice and their distribution and biodegradation properties were studied.

RESULTS

After intravenous injection. 111In-PLGA was rapidly eliminated from the plasma and recovered mainly in the kidneys and urine. Approximately 15% of the dose was recovered in the liver, predominantly in the nonparenchymal cells. 111In-Gal-PLGAs were taken up by the liver parenchymal cells. Derivatives having 16 or more galactose residues were taken up by the liver to a higher extent (> 60% of the dose). The hepatic clearance of 111In-Gal-PLGAs correlated with their number of galactose residues. 111In-Gal18-PLGA was degraded into low-molecular weight products in the liver.

CONCLUSIONS

The advantageous in vivo properties of Gal-PLGA as a liver-specific biodegradable carrier of drugs were demonstrated in mice.

Analysis of the thromboxane/prostacyclin balance in human urine by gas chromatography/selected ion monitoring: abnormalities in diabetics

We microanalyzed 2,3-dinor-6-keto-prostaglandin F1 alpha (2,3-dinor-6-keto-PGF1 alpha 1) and 11-dehydrothromboxane B2 (11-dehydro-TXB2, 2) in human urine. Samples containing a [2H4]-analogue as an internal standard were extracted by chromatography using Sep Pak tC18 and silica gel. The compounds were then analysed by means of the lactone ring opening reaction and dimethylisopropylsilylation. The conversion of 1 to 1-methyl ester (ME)-propylamide (PA)-9, 12, 15-dimethylisopropylsilyl (DMIPS) ether derivative and of 2 to 1-ME-6-methoxime (MO)-9, 12, 15-tris-DMIPS ether derivative was followed by gas chromatography/selected ion monitoring (GC/SIM). Interfering substances from the urine matrix were eliminated during GC/SIM analysis using a DB-5 column. We were able to detect 1 (222-1031 pg/mg creatinine) and 2 (18-155 pg/mg creatinine) in human urine. Furthermore, the thromboxane/prostacyclin (IX/PGI) ratio in the urine of diabetics was higher than that of healthy volunteers. This method can be used to determine the TX/PGI balance in human urine.

Involvement of the endogenous opioid system in the drinking behavior of schizophrenic patients displaying self-induced water intoxication: a double-blind controlled study with naloxone

Previously we found significant suppression of polydipsia in a schizophrenic patient with PIP syndrome (psychosis, intermittent hyponatremia, and polydipsia). Suppression was obtained with a small dose of naloxone injected once every 2 weeks in long-term repeated studies. We attempted to confirm the effect of naloxone on PIP syndrome by using a double-blind controlled study. The body weights of eight schizophrenic inpatients with PIP syndrome were checked five times daily, and the maximum weight gain during 1 day was chosen as an index of their polydipsia. Naloxone (0.6 mg in three divided doses) or placebo (saline) injection was given once every 2 weeks three times. Assignment to either the naloxone or placebo series was done randomly in a double-blind, crossover design. Naloxone decreased the maximum weight gain per day significantly in five cases. However, naloxone also increased weight gain significantly in three cases. There was no correlation of the weight-increasing effect of naloxone with the duration and intensity of excessive drinking. Our findings showed that the endogenous opioid system might be related to compulsive drinking behavior in the PIP syndrome and that opioid antagonists such as naloxone or naltrexone could be useful in the therapy of PIP syndrome.

Very poor prognosis in cases with extravasation of the contrast medium during angiography

BACKGROUND

The rebleeding of a ruptured intracranial aneurysm in the acute stage has been thought to indicate a very poor prognosis. In our experience, the outcome of patients with extravasation of the contrast medium is worse than that of patients with rerupture under circumstances other than angiography. We demonstrated the poorer outcome of the patients with extravasation, compared to that of the patients developing rerupture under circumstances other than angiography, and examined the factors that contributed to the poorer outcome of the patients with extravasation.

METHODS

Among the 641 cases of ruptured intracranial aneurysm, we have handled over the past 10 years, 36 (5.6%) patients have rebled before surgery was performed. Thirteen patients rebled during angiography (Group I), and the remaining 23 patients rebled in other circumstances (Group II). We compared the outcome of both groups.

RESULTS

The rebleeding occurred within 6 hours of the initial rupture in 29 (80%) patients. The outcome of Group I was significantly poorer than that of Group II (p < 0.05). In Group I, SD was achieved in only 1 patient and the remaining 12 patients died, while in Group II, 8 patients were in GR or MD, 2 were in SD, and the remaining 13 patients died.

CONCLUSION

Because rebleeding during angiography most often occurs in the acute stage and because the outcome of patients with extravasation is very poor, we recommend that the performance of angiography be delayed at least between 3 and 6 hours after the initial rupture.

Cerebrospinal fluid levels of soluble tumour necrosis factor receptor in acute encephalitis

Soluble tumour necrosis factor receptor (sTNF-R) inhibits the action of TNF-alpha. The level of sTNF-R reflects the true biological activity of TNF-alpha. We investigated whether sTNF-R in cerebrospinal fluid (CSF) and serum increases during the acute stage in patients with acute encephalitis by measuring p60 sTNF-R using a sandwich enzyme immunoassay. The levels of sTNF-R were significantly higher in the CSF and serum of children with acute encephalitis than in those of control subjects. The patients with acute encephalitis who died or had severe neurological sequelae had higher CSF sTNF-R levels than those who survived. There were no significant differences in the serum sTNF-R, serum C-reactive protein and CSF protein levels, and CSF cell counts between the two groups. The sTNF-R levels of 4.0 ng/ml or higher identified patients with acute encephalitis who had neurological sequelae with a sensitivity of 100% (8/8), a specificity of 100% (8/8%), and a predictive value of 100% (8/8). The 95% confidence interval for these three values is 63-100%. Our findings suggest that the CSF level of sTNF-R during the acute stage of encephalitis is important for predicting neurological sequelae.

Muscarinic and beta-adrenergic receptor expression in peripheral lung from normal and asthmatic patients

We used human peripheral lung from 8 mildly asthmatic patients and 11 normal donors to study the expression of muscarinic and beta-adrenergic receptors in asthma. There was no significant difference in the affinity or the density of muscarinic (labeled with [N-methyl-3H]scopolamine) and beta 1- and beta 2-adrenergic receptors (labeled with [125I]iodocyanopindolol) in peripheral lung from asthmatics compared with nonasthmatics. Only the muscarinic m1 receptor mRNA was detected in human lung using Northern blot analysis. Additionally, peripheral lung cellular mRNA hybridized to human beta 1 and beta 2 cDNA probes, giving 3.2- and 2.2-kb hands corresponding to beta 1 and beta 2-adrenergic receptors mRNA, respectively. Densitometric scanning of the autoradiograms suggests that there was no significant difference in the relative abundance of muscarinic m1 and beta 1- and beta 2-adrenergic receptor mRNA in asthmatic compared with nonasthmatic lungs. Functional experiments obtained in trachea suggest that there was an increase in the cholinergic neural response evoked by electrical field stimulation in asthmatic compared with nonasthmatic tissues which was not due to a reduction in inhibitory noncholinergic nonadrenergic relaxations.

A case of large neonatal arteriovenous malformation with heart failure. Color Doppler sonography, MRI and MR angiography as early non-invasive diagnostic procedures

We report a case of a large arteriovenous malformation (AVM) of neonatal onset with heart failure. Transfontanel color Doppler sonography revealed abnormal vessels in the early stage of the investigation. Magnetic resonance imaging (MRI) revealed numerous flow voids suggesting abnormal vessels, and magnetic resonance angiography (MRA) disclosed numerous bizarre abnormal vessels. Color Doppler sonography is a convenient and appropriate procedure for the early bedside diagnosis of neonatal AVMs. MRI and MRA can replace cerebral angiography for the diagnosis of neonatal AVMs.

Optic nerve hypoplasia with hypopituitarism and an arachnoid cyst

We describe a 5-month-old boy with bilateral optic nerve hypoplasia associated with visual impairment, growth hormone deficiency and an arachnoid cyst in the right temporal lobe on MRI. Optic nerve hypoplasia is sometimes associated with agenesis of the septum pellucidum, commonly known as septo-optic dysplasia, and/or hypopituitarism. There have been a few reports about its association with other abnormalities of the central nervous system, but none about that with an arachnoid cyst.

[Vertebral artery dissection without subarachnoid hemorrhage studied by serial angiography]

We presented six cases we have encountered of vertebral artery dissection without subarachnoid hemorrhage followed by serial angiography. All six patients suffered from severe headache and/or nuchal pain at onset. Pain was acute at onset, with severe intensity and sharp quality and was located unilaterally on the dissection side. Only two patients showed neurological deficits. CT scan disclosed no abnormalities in any of the cases and angiography performed at the acute stage showed varied findings. The so-called pearl and string sign, which has been considered the most common finding of this disorder, was observed in only two cases. The definite diagnosis was able to be finally made by serial angiography. During the first few months after onset, dynamic changes of angiographical findings were demonstrated in all cases. During these periods, although transient deterioration of the angiographical findings was shown in four cases, spontaneous healing or improvement was finally recognized in all cases except one which progressed to total occlusion. In contrast to this, in the chronic stage, no changes of angiographical findings occurred in any of the cases. All six patients were treated non-surgically. All showed almost total recovery from symptoms and returned to their previous life styles. There were no cases of recurrent deterioration of symptoms in spite of the changes indicated by the angiographical findings. Our experience with these patients suggests that the actual incidence of vertebral artery dissection without subarachnoid hemorrhage may be much higher than is usually thought, and that the natural course of this disorder seems to be usually favorable. However, longer follow-up study and an analysis of a larger number of cases are required to identify the true incidence and the natural course of this disorder. In addition, we would like to emphasize that accurate diagnosis is most important. If it is clinically suspected, careful investigations including serial angiography should be carried out for the diagnosis of this disorder.

Localisation and expression of beta-adrenoceptor subtype mRNAs in human lung

The cellular localisation and distribution of mRNAs encoding beta-adrenoceptor subtypes in human lung were studied by in situ hybridisation and Northern blot analysis. The 851-bp SmaI/PvuII fragment of human beta 1-adrenoceptor cDNA, the 439-bp SmaI fragment of human beta 2-adrenoceptor cDNA and the 975-bp SmaI fragment of human beta 3-adrenoceptor cDNA bound to single mRNA species of approximately 3.2 kb, 2.2 kb and 2.3 kb in size, respectively. Human lung and heart and rabbit lung expressed both beta 1- and beta 2-adrenoceptor mRNAs with no detectable level of beta 3-adrenoceptor mRNA, while rabbit perirenal adipose tissue expressed beta 1-, beta 2- and beta 3-adrenoceptor mRNAs. Cultured human airway epithelial cells and airway smooth muscle cells expressed only beta 2-adrenoceptor mRNA. In situ hybridisation in human lung, using 35S-labelled antisense RNA probes revealed a high level of expression of beta 1- and beta 2-adrenoceptor mRNAs in the pulmonary blood vessels, high level of expression of beta 2-adrenoceptor mRNA in the alveolar walls with less expression of beta 1-adrenoceptor mRNA. There was a moderate expression of beta 2-adrenoceptor but not beta 1-adrenoceptor mRNA in airway epithelium and smooth muscle of peripheral airways and no detectable beta 3-adrenoceptor mRNA in any lung structures.

Proctolinlike immunoreactivity and identified neurosecretory cells as putative substrates for modulation of courtship display behavior in the blue crab, Callinectes sapidus

Pheromonally stimulated courtship display (CD) behavior in male blue crabs (Callinectes sapidus) is characterized by rhythmic waving of the fifth legs. The waving of the fifth legs is modulated by proctolin in freely moving crabs and in reduced preparations. To begin to identify an anatomical substrate for CD behavior we have localized putative proctolinergic cells and described the morphology of neurosecretory neurons known to oscillate during pheromonal stimulation of reduced preparations. Proctolin-induced CD occurs with developmental and seasonal dependence. Male crabs altered hormonally by eyestalk ligation spontaneously produce CD behavior. We have localized proctolinlike immunoreactivity (PIR) in the central nervous system (CNS) and compared this immunoreactivity across sexes, developmental stage, eyestalk ligation, and seasonal conditions to determine whether or not expression of PIR is correlated with CD behavior. PIR was found in most areas of the CNS. Clusters of PIR-positive cells were found in the sinus gland and eyestalk ganglia, olfactory neuropil with associated cell bodies, and in a large cell cluster in the subesophageal region of the ventral nerve cord. Three pairs of cell bodies in different cell body groups in the brains of adult crabs stained positively for PIR but did not stain in the youngest juvenile animals. Comparison of PIR distribution with toluidine blue studies of the ventral nerve cord indicated a high likelihood that cells in the PIR-positive cluster of the subesophageal ganglia were also members of the cluster of neurons identified as oscillatory neurosecretory neurons.

1 alpha,25-dihydroxyvitamin D3-induced upregulation of calcineurin during leukemic HL-60 cell differentiation

Cyclosporin A and FK506, at concentrations that inhibited phosphatase activity of calcineurin in HL-60 cellular lysates, augmented the proliferation of leukemic HL-60 cells. These immunosuppressants did not affect 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3]-induced monocytic differentiation of HL-60 cells, but did abrogate the 1,25(OH)2D3-induced inhibition of HL-60 cell growth. Treatment with 20 nmol/L 1,25(OH)2D3 led to a progressive increase in calcineurin phosphatase activity in subcellular fractions from HL-60 cell extracts, the increase in this activity appeared to parallel the phenotypic and functional changes of HL-60 cells during monocytic differentiation induced by 1,25(OH)2D3. Immunoblot analysis indicated that increase in calcineurin activity was concordant with the increased expressions of calcineurin catalytic subunit isozymes, calcineurin A alpha (CNA alpha), and calcineurin A beta(CNA beta), and a regulatory calcineurin B subunit (CNB) proteins, which were preceded by a coordinate increase in the levels of CNA alpha, CNA beta and CNB mRNAs. The expression of calmodulin remained unaltered throughout 1,25(OH)2D3-induced monocytic differentiation. These results suggest that calcineurin activation has a net negative effect on HL-60 cell proliferation, and that the increased expression of calcineurin may be involved in 1,25(OH)2D3-induced inhibition of HL-60 cell proliferation.

Non-traumatic arteriovenous fistulas of the scalp treated by a combination of embolization and surgical removal

Three patients with non-traumatic arteriovenous fistulas (AVFs) of the scalp were treated by embolization using acrylate glue through the transarterial route or by direct puncture of the lesions and then surgical resection. Complete cure was achieved in all three patients. Selective angiography is indispensable in the correct diagnosis of scalp AVFs. Embolization facilitates surgical removal when necessary, and this combination is the treatment of choice for scalp AVFs.

Docosahexaenoic acid reduces GABA response in substantia nigra neuron of rat

.1. The effects of docosahexaenoic acid (DHA) on gamma-aminobutyric acid (GABA) response (IGABA) were investigated on the neuron acutely dissociated from rat substantia nigra (SN), with the use of patch recordings in a whole cell mode. 2. DHA (5 x 10(-6) M) reduced bicuculline-sensitive GABA (10(-4) M) current by 50.3 +/- 13.1% (mean +/- SE) at a holding potential (Vh) of -40 mV under voltage clamp. 3. The GABA concentrations for the half-maximum and threshold of IGABA were not altered by the presence or absence of 5 x 10(-6) M DHA in the external solution. 4. The decrease of 10(-4) M IGABA, following the peak during GABA application, was more rapid in the presence of 5 x 10(-6) M DHA than in its absence. The time constants for IGABA decay were significantly different between the two conditions. 5. DHA reduced the IGABA and the glycine-induced response (Igly) in a concentration-dependent manner. On the contrary, DHA potentiated the aspartate-induced response (Iasp) in a concentration-dependent manner, suggesting that DHA influences the activity of chloride channels but does not exhibit a nonspecific blocking effect on any ionic channel. 6. The application of thimerosal did not affect the reduction of IGABA by DHA, suggesting it unlikely that DHA reduces the IGABA by binding to phospholipids or triglycerides and altering the lipid environment around the chloride channel. 7. Arachidonic acid (AA) also reduced the IGABA in a manner similar to DHA. Docosapentaenoic acid (DPA) reduced the IGABA less potently than DHA. Other polyunsaturated and saturated fatty acids, such as docosatrienoic acid, docosatetraenoic acid, palmitic acid, and oleic acid, had very little or no effect on the IGABA. 8. DHA, as well as AA, may play an important role in modulating neuronal excitability by reducing the IGABA and Igly, and potentiating N-methyl-D-aspartate receptor-mediated responses in the SN.

Optimal oxygen tension conditions for functioning cultured hepatocytes in vitro

With a view toward furthering the development of artificial liver systems, we have been culturing hepatocytes in vitro. The object of this research was to investigate the ideal conditions of oxygen tension for the efficient functioning of hepatocytes. Viable hepatocytes isolated from rat livers were cultured under five different oxygen tensions: 5, 10, 20, 50 and 90% O2. DNA contents, gluconeogenesis, urea synthesis, adenosine triphosphate (ATP) levels, and lipid peroxidation of hepatocytes were evaluated. Under the 5% oxygen conditions, the function of hepatocytes was very inferior and was accompanied by a low ATP level. However, hepatocytes cultured under 90% oxygen tension functioned less effectively than the control (20% O2) with elevated lipid peroxidation. The data in this study suggest that the optimum oxygen condition for cultured hepatocytes is 10 approximately 50%, and that especially under conditions of 20% oxygen tension, i.e., that of the ordinary atmosphere, hepatocytes can function most effectively.

A role for Rev in the association of HIV-1 gag mRNA with cytoskeletal beta-actin and viral protein expression

Human immunodeficiency virus type-1 (HIV-1) Rev acts by inducing the specific nucleocytoplasmic transport of a class of incompletely spliced RNAs that encodes the viral structural proteins. The transfection of HeLa cells with a rev-defective HIV-1 expression plasmid, however, resulted in the export of overexpressed, intron-containing species of viral RNAs, possibly through a default process of nuclear retention. Thus, this system enabled us to directly compare Rev+ and Rev+ cells as to the usage of RRE-containing mRNAs by the cellular translational machinery. Biochemical examination of the transfected cells revealed that although significant levels of gag and env mRNAs were detected in both the presence and absence of Rev, efficient production of viral proteins was strictly dependent on the presence of Rev. A fluorescence in situ hybridisation assay confirmed these findings and provided further evidence that even in the presence of Rev, not all of the viral mRNA was equally translated. At the early phase of RNA export in Rev+ cells, gag mRNA was observed throughout both the cytoplasm and nucleoplasm as uniform fine stippling. In addition, the mRNA formed clusters mainly in the perinuclear region, which were not observed in Rev+ cells. In the presence of Rev, expression of the gag protein was limited to these perinuclear sites where the mRNA accumulated. Subsequent staining of the cytoskeletal proteins demonstrated that in Rev+ cells gag mRNA is colocalized with beta-actin in the sites where the RNA formed clusters. In the absence of Rev, in contrast, the gag mRNA failed to associate with the cytoskeletal proteins. These results suggest that in addition to promoting the emergence of intron-containing RNA from the nucleus, Rev plays an important role in the compartmentation of translation by directing RRE-containing mRNAs to the beta-actin to form the perinuclear clusters at which the synthesis of viral structural proteins begins.

Bisphosphonates act on osteoblastic cells and inhibit osteoclast formation in mouse marrow cultures

We examined the mode of action of bisphosphonates on osteoclastic cell recruitment using mouse marrow cultures with or without osteoblastic cells. Tartrate-resistant acid phosphatase-positive multinucleated cells [TRAP(+)MNC] formed in cultures were determined to be osteoclastic cells. In marrow cultures, TRAP(+) MNC formation in the presence of 10(-8) mol/L 1,25(OH)2D3 was not affected by the addition of 10(-6) mol/L dihydrogen (cycloheptylamino)-methylenebisphosphonate monohydrate (YM175). However, it was inhibited in cocultures of marrow cells with osteoblastic cells. The inhibitory effect was evident throughout the entire culture period. YM175 dose dependently inhibited TRAP(+) MNC formation, and other bisphosphonates--pamidronate and alendronate--also inhibited TRAP(+) MNC formation in the coculture. Similar observations were also made in the coculture of spleen cells with osteoblastic cells. The conditioned media of osteoblastic cells treated with 10(-6) mol/L YM175 inhibited TRAP(+) MNC formation in marrow cultures. The presence of YM175 in methylcellulose cultures affected neither the colony formation of monocyte-macrophage lineage, nor TRAP(+) MNC formation in the succeeding cocultures of recovered cells with osteoblastic cells. These results indicate that YM175 and probably other bisphosphonates as well preferentially inhibit the later stage of osteoclastogenesis through its action on osteoblastic cells. Our findings suggest that part of the inhibitory action by osteoblastic cells in the presence of bisphosphonates is mediated through soluble factor(s).