Purification and biochemical characterization of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate-sensitive L-glutamate receptors of pig brain

Two preparations of glutamate receptors were purified from the synaptic junctions of pig brain by a combination of detergent solubilization, anion-exchange chromatography, wheat-germ agglutinin affinity chromatography and sedimentation through sucrose gradients. These preparations were enriched in specific L-[3H]glutamate binding activity (> 5000 pmol of glutamate binding sites/mg of protein), and the rank order of ligand affinity for binding to these preparations was: quisqualate > 6-cyano-7- nitroquinoxaline-2,3-dione > alpha-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid (AMPA) > L-glutamate > kainate > > N-methyl-D-aspartate approximately L-2-amino-4-phosphonobutyrate. SDS/PAGE analysis revealed that more than 80% of the protein in either of these preparations appeared as a single protein band of 106 kDa. Two-dimensional gel electrophoresis further revealed that these 106 kDa proteins consisted of a series of acidic proteins which were recognized by antibodies against rat AMPA receptor subunits. These 106 kDa proteins were also recognized by wheatgerm agglutinin and concanavalin A; in addition, peptide N-glycosidase F treatment of these preparations decreased their size to 99 kDa. Our results suggest that the putative glutamate receptors isolated here are likely to belong to the AMPA subtype of glutamate receptors in pig brain. Using the purification procedure reported here, 5 micrograms of AMPA receptor proteins can be isolated from 250 g of pig brain tissue.

2-D time-of-flight (TOF) MRA of thrombophlebitis of upper extremity and subclavian veins. A case report

In this report, the authors present a case of segmental thrombosis of left subclavian vein that was inaccessible to conventional venography and inconclusive in magnetic resonance techniques (spin echo, gradient echo) but was clearly demonstrated by two-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA). This technique is very sensitive to detect slow flow or partial occlusion of the vessels and is of great help in solving the problem of axillary-subclavian venous obstruction or thrombophlebitis.

Epidermal denervation and its effects on keratinocytes and Langerhans cells

Skin innervation has been considered to subserve sensory perception only, but several lines of evidence suggest that there are "effector' influences of skin innervation on the immune system and keratotinocytes. In this study, we transected the sciatic nerves of rats and examined the effects of denervation on the epidermis. In normal skin, the epidermis was densely innervated by fine axons that were immunostained with several axonal markers, including neuronal ubiquitin carboxyl terminal hydrolase (protein gene product 9.5). All of the epidermal axons in the regions innervated by sciatic nerve disappeared within 24-48 h after transection of sciatic nerve, and remained absent as long as subsequent reinnervation by regenerating axonal sprouts was prevented. Denervation produced changes in both the keratinocytes and the Langerhans cells, the bone marrow-derived antigen-presenting cells of the epidermis. The thickness of epidermis decreased within 7 days. By 48 h after transection, the Langerhans cells and their dendritic processes became intensely immunoreactive for protein gene product. Protein gene product 9.5 expression on Langerhans cells remained prominent as long as skin was denervated, but disappeared with reinnervation. By reverse transcription-polymerase chain reaction, we demonstrated the presence of the transcripts for protein gene product 9.5 in epidermis, consistent with the synthesis of the protein by the Langerhans cells. We conclude that epidermal sensory fibres have novel influences on both keratinocytes and Langerhans cells of the epidermis.

Observation of bolus position with standardized test foods and fluoroscopic technique

Sugar and agar balls containing barium were made for the fluoroscopic observation of the bolus position during habitual side chewing in 13 adult males (aged from 20 to 28 years) who had a complete dentition and healthy masticatory system. The test foods had constant size, shape, weight and known hardness, i.e. type 1, 20 kg; type 2, 40 kg; type 3, 1.0 kg and type 4, 0.5 kg. These four types of test foods were chewed randomly in a fluoroscopic room. The jaw separation distance and the bolus position during first bite and crushing bite were observed. The influence of the chewing order of four types of test foods on the bolus position was also recorded. It was found that both hard and soft test foods were most often crushed at the first molar area, and the separation distance during the crushing bite was only slightly wider than the diameter of the food. The first bite jaw separation distance for hard food chewing was significantly wider than soft food chewing and the later in the chewing order the wider the separation distance. The effect of chewing order was not significant on the position and jaw separation distance of the crushing bite.

Is ataxic gait the predominant presenting manifestation of Creutzfeldt-Jakob disease? Experience of 14 Chinese cases from Taiwan

Creutzfeldt-Jakob disease (CJD) is caused by an unusual prion protein. Rare CJD cases have been reported in Chinese individuals. This report describes the clinical manifestations of 14 Chinese individuals with clinically definite CJD from the National Taiwan University Hospital during the period 1976-1995. It is the largest case series of Chinese CJD up to now. All these patients fulfil the clinical definite diagnosis of CJD proposed by Brown et al. (1986), including rapidly evolving dementia, myoclonus, periodic electroencephalographic (EEG) activity (0.5-2 Hz) and death within 12 months. The clinical characteristics of the present series, including age at onset, sex ratio, duration, initial symptoms, neurological signs, EEG abnormalities, and neuroimaging studies were similar to those reported in other countries. However, there is a high incidence of initial ataxic gait as the presentation in our patients. Eight (57%) out of 14 patients initially had gait ataxia alone or in association with dementia. CJD should be considered in the differential provisional diagnosis of any middle-aged patient with a progressive ataxic syndrome.

Effects of castration and androgen replacement on tumour growth of human hepatocellular carcinoma in nude mice

BACKGROUND/AIMS

Previous clinical investigations suggest that androgen and its receptor (AR) may play an important role in the growth of hepatocellular carcinoma. Few studies are available concerning the effect of androgen manipulation on the growth of AR-positive hepatocellular carcinoma in vivo.

METHODS

AR-positive (SM10) and AR-negative (SM2) sublines derived from a human hepatocellular carcinoma line KYN-1 were implanted subcutaneously in the lower abdomen of nude mice. The tumour size and expression of proliferating cell nuclear antigen and Lewis Y antigen were examined in intact males, castrated males, intact females, and castrated males with androgen replacement. AR of the tumour was measured with binding assay, ultracentrifugation, and Western blotting.

RESULTS

The growth of SM10 was significantly better in intact males and castrated males with 5a-dihydrotestosterone injection than in intact females and castrated males. Castration did not suppress the growth of SM2. The tumour AR level was reduced by castration but maintained by the hormone substitution. Although proliferating cell nuclear antigen expression was closely associated with tumour growth, Lewis Y antigen expression did not differ among the groups.

CONCLUSIONS

These data may indicate that this hepatocellular carcinoma subline (SM10) is androgen-responsive and that androgen ablation can cause the inhibition of the tumour growth, which might be due to decreased proliferative and not increased apoptotic activities. In addition, such androgen-stimulated tumour growth seems to be mediated through AR.

A solitary congenital self-healing histiocytosis. Report of a case and review of the literature

Congenital self-healing histiocytosis (CSHH), and especially the solitary variant, is a rare primary skin disorder. We report on a newborn with a congenital solitary ulcerated skin nodule. Extracutaneous involvement was not found. A skin biopsy was performed at the age of 44 days and revealed a dense dermal infiltrate of large histiocytic cells. Immunohistochemical study revealed that the cells of the dermal infiltrate were Langerhans' cells which were strongly positive for S- 100 and negative for lysozyme, leukocyte common antigen and alpha-1-antichymotrypsin. The skin lesion involuted spontaneously over the next month without any treatment. The clinical, histopathological and immunohistochemical results fulfilled the criteria of solitary CSHH. We herein report the first case of CSHH in Taiwan and the twelfth case of solitary CSHH in the world.

Reverse jugular flow in a case of thrombosis of the brachiocephalic vein with an artificial arteriovenous fistula

Thrombosis of the thoracic inlet veins following placement of a central venous catheter is a well-known complication, and several findings have been reported by color Doppler sonography. However, reverse jugular flow resulting from this complication is rarely mentioned and should be differentiated from another complication of iatrogenic arteriovenous fistula between neck vessels. The authors here describe a uremic patient with an artificial arteriovenous fistula in the forearm complicated with thrombosis of the ipsilateral brachiocephalic vein. Factors permitting the differential diagnosis by coloer Doppler sonography and clinical conditions are proposed.

The second capsule gene of cryptococcus neoformans, CAP64, is essential for virulence

The extracellular polysaccharide capsule produced by Cryptococcus neoformans is essential for its pathogenicity. We have isolated and characterized a gene, (AP64, which is required for capsule formation. An encapsulated strain created by complementation of the cap64 mutation produced fatal infection of mice within 25 days, while the cap64 acapsular strain was avirulent. Gene deletion of CAP64 from a wild-type strain resulted in the loss of capsule as well as virulence. Contour-clamped homogeneous electric field gel analysis indicates that CAP64 is located on chromosome III which is different from the localization of another capsule-related gene, CAP59. The nonlinkage between CAP64 and CAP59 was also supported by classical recombinational analysis. Database searches did not reveal any sequence with high similarity to CAP64. We also found that the CAP64 locus is contiguous to a convergently transcribed gene which has significant similarity to the gene encoding the yeast proteasome subunit, PRE1. The distance between the cDNA ends of these two genes is only 22 bp. This study confirms the previous molecular genetic evidence that capsule is an essential factor for the virulence of C. neoformans in the murine model.

Pneumothorax after small-bore catheter placement for malignant pleural effusions

OBJECTIVE

The objective of this study was to evaluate the incidence and significance of pneumothorax after small-bore chest tube placement for symptomatic malignant pleural effusions.

SUBJECTS AND METHODS

Over a 2-year period, 90 patients with a known primary malignant tumor and symptomatic pleural effusion were referred to the radiology service at Duke University Medical Center. All patients underwent placement of a small-bore chest tube with fluid drainage in preparation for intrapleural sclerotherapy. Two of these patients were excluded because of coexisting empyema (n=1) and thoracentesis (n=1). The remaining 88 patients (30 men and 58 women; 26-86 years old [mean, 60 years old], who had 90 chest tubes placed, formed our study group. The incidence, duration, and clinical significance of their pneumothoraces and the amount of pleural effusion drained were recorded.

RESULTS

Among the 88 patients with 90 chest tubes, 27 patients with 28 chest tubes (31%) were found to have pneumothorax after the procedure. For 23 patients with 24 chest tubes, pneumothorax was evident on chest radiographs taken immediately after tube insertion and fluid drainage. Four patients with four chest tubes were found to have pneumothorax on chest radiographs taken the next day. No significant difference in the amount of fluid drained during the procedure was noted for patients with or without pneumothorax (831 ml versus 853 ml). No relationship between the size of each pneumothorax and the size of each drainage catheter was seen. The duration of pneumothorax ranged from 2 hr to 18 days (average, 3.5 days). Resolution of pneumothorax was seen in 22 (79%) of 28 cases; the remaining six cases of pneumothorax (21%) were stable, and the patients showed eventual fluid reaccumulation after chest tube removal and no sclerotherapy. No patient developed tension pneumothorax, respiratory distress, or other complications.

CONCLUSION

Pneumothorax should be recognized as a common finding after chest tube placement and immediate fluid drainage for malignant pleural effusions. We suggest that this finding is related to rapid removal of fluid from a relatively stiff, noncompliant lung. Patients whose lungs do not fully re-expand in several days will probably not benefit from sclerotherapy. Their tubes may be removed without risk of an enlarging tension pneumothorax.

Acute disseminated encephalomyelitis in children: clinical, neuroimaging and neurophysiologic studies

Nine patients below 20 years of age (4 males and 5 females), who were diagnosed to have acute disseminated encephalomyelitis (ADEM) by clinical findings and magnetic resonance imaging (MRI), were reviewed retrospectively. They ranged from 4 months to 20 years of age with an average of 8.6 years. Seven patients (78%) received neurophysiological studies, which included electroencephalography, multimodality evoked potentials (EPs), nerve conduction velocity and/or F-wave measurement. The presentation symptoms were mainly headache, vomiting, consciousness change and motor deficits. Seven (78%) of nine patients had symptoms preceded by fever or upper respiratory tract infections; one (11%) was preceded by trivalent mumps, measles, rubella vaccination and no definite predisposing factor was found in another. Computed tomography (CT) scans were abnormal in five (71 %) of seven children, while MRI showed multiple lesions in seven (78%) of nine children. The lesions in MRI were mainly in the brainstem (n = 6), basal ganglion (n = 5), thalamus (n = 4), periventricular white matter (n = 4) and cerebellum (n = 4). EPs disclosed spinal cord involvement in all patients who received the examination. Peripheral neuropathy was disclosed in one patient. It was concluded that associated radiculoneuropathy is possible in patients with ADEM. Both MRI and neurophysiologic studies are complementary for diagnosis of ADEM.

High-resolution computed tomography in pulmonary lymphangio(leio)myomatosis and pulmonary tuberous sclerosis

We report two cases where high-resolution computed tomography (HRCT) assisted in the diagnosis of a patient with lymphangioleiomyomatosis and a patient with pulmonary tuberous sclerosis. HRCT was used in both cases where the chest radiographs and conventional computed tomographic scans appeared relatively normal but the conditions were strongly suspected.

Assaying the activity of HIV-1 integrase with DNA-coated plates

Integration of reverse transcribed viral DNA of HIV into host chromosomes is mediated by the viral enzyme, integrase. This enzymatic activity can be monitored in vitro by integration of a small labeled DNA (donor) into a second unlabeled DNA (target). The methodology usually involves isotope labeling and gel electrophoresis. To simplify the measurement, a method mimicking enzyme-linked immunosorbent assay (ELISA) procedures was developed. Fragments of DNA were adsorbed directly on 96-well plates and used as the target DNA. The donor was a synthetic 21-bp DNA duplex of HIV-1 U5 LTR; biotin was incorporated into the 5' end of one strand whose two nucleotides at the 3' end were specifically removed during the integration. As a result of integration, the biotin-labeled donor DNA was joined with the target DNA and became immobilized on plates. These integration products were then measured by binding of avidin-alkaline phosphatase on plates. The method is simple and straightforward and can easily be adapted for high throughput screening of integrase inhibitors.

Renal neural response to ischemic renal failure in chronic hypoxic rats

This report was designed to assess response of the renal nerve activity (RNA) during and after renal ischemia in chronic hypoxic rats. Hypoxia was induced by placing the female Wistar rats in an altitude chamber set at 5500 m for 4 weeks. Simultaneous recordings of left renal efferent (RENA) and afferent (RANA) nerve activity were performed in each pentobarbital-anesthetized rat throughout the experiment. Ischemic renal failure was induced by complete occlusion of the left renal artery for 45 min. During renal arterial occlusion (RAO), RENA gradually decreased while RANA enhanced initially and then this decreased gradually in both sea level (SL) controls and chronic hypoxic (high-altitude; HA) rats. During 45 min of reperfusion, RENA depressed more in comparison with RANA in both groups of animals. In addition, RANA returned to baseline level in SL rats, while it remained elevated in HA rats. In the second experiment, six groups of renal ischemic rats were challenged by rapid intravenous infusion of 10 ml of saline, and urine was collected for 90 min from the left ureter. Baseline RENA was low in rats 4 h after RAO of SL (4SL) and of HA (4HA) groups. The effects of saline loading on RENA and RANA were different in HA and SL rats. Saline loading significantly decreased RENA but increased RANA more in SL rats. Following saline loading, RENA in 4SL and 4HA rats, as well as animals 24 h after RAO of SL (24SL) and HA (24HA) were comparable to their respective SL or HA animals. In 4SL rats, RANA was significantly enhanced, and remained elevated during saline loading and the recovery period. In 4HA, 24HA and 24SL rats, RANA reduced significantly during saline loading, then its activity returned to the baseline value. The insulted kidneys showed increased renal excretion of water and sodium in 4SL and 4HA rats. Urinary excretion reduced significantly in 24SL rats but was almost normal in 24HA rats. These results indicate that a decrease in RENA may play a protective role in response to renal ischemia in both SL and HA rats. In response to renal ischemia and saline loading, different alterations of RANA in SL and HA rats may reflect a beneficial mechanism located in the hypoxia-pretreated kidney.

Significance of hemoptysis following thrombolytic therapy for acute myocardial infarction

PURPOSE

To describe the occurrence, cause, and significance of hemoptysis following thrombolytic therapy for acute myocardial infarction.

PATIENTS AND METHODS

We retrospectively reviewed 2,634 patients presenting with acute myocardial infarction who received thrombolytic therapy to determine the incidence of hemoptysis. Chart and radiographic review included the type, dose, and route of thrombolytic therapy. In addition, the onset, duration, and severity of hemoptysis were recorded and correlated with radiographic and bronchoscopic findings.

RESULTS

Eleven patients (0.4%) developed hemoptysis following administration of thrombolytic therapy for an acute myocardial infarction. The duration and severity had a wide range, although no patient had significant hemodynamic compromise. The source of hemoptysis was identified in only one patient who had a tongue laceration following cardiopulmonary resuscitation, and blood was seen within the oropharynx and trachea. No definitive cause was identified in all other patients. There was no correlation between the different types or doses of thrombolytic therapy and the duration or severity of hemoptysis. Chest radiographs were nonspecific and demonstrated resolution within 11 days following hemoptysis. CT of the thorax in one patient and bronchoscopy in two patients confirmed chest radiographic findings and in no patient was an underlying pulmonary abnormality identified.

CONCLUSIONS

Pulmonary hemorrhage and hemoptysis are unusual complications of thrombolytic therapy in patients with acute myocardial infarction. Although hemoptysis may be the first indicator of an underlying pulmonary abnormality, we found no case in which a significant abnormality was unmasked. This study suggests that follow-up chest radiographs are recommended and further evaluation may be unnecessary if complete resolution is demonstrated.

Effects of paraquat on the substantia nigra of the wistar rats: neurochemical, histological, and behavioral studies

Effects of paraquat on the substantia nigra of the male Wistar rats we re studied pharmacologically by a intracerebral injection of paraquat. The neurochemical, morphological, and behavioral changes observed after a unilateral intranigral injection of paraquat (1-5 microgram) were as follows: (1) neurochemically, paraquat caused dose-dependent depletion of dopamine in the ipsilateral striatum starting 2 weeks after treatment; this effect was long-lasting and irreversible. The ipsilateral striatal dopamine level in animals treated with 3 microgram paraquat was even decreased by 91.5%. (2) Morphologically, 2 microgram of paraquat produced marked loss of Nissl substances and prominent glial reaction in the substantia nigra, while 3 microgram of paraquat caused a severe loss of neurons. (3) Behaviorally, paraquat caused a vigorous rotational behavior in rats contralateral to the lesioned side in response to apomorphine administration (0.5 mg/kg, sc). This effect was dose-dependent and lasted for the entire 16-week experimental period. Taken together, these data indicate that intranigrally injected paraquat may possess marked neurotoxicity and induce degeneration of the rat nigrostriatal dopaminergic system.

Frequency of linear hyperechogenicity over the basal ganglia in young infants with congenital rubella syndrome

Five young infants with congenital rubella syndrome (CRS) underwent cranial ultrasonographic examinations and/or computed tomographic examinations. Only two of these infants were small for their gestational age, and none of them were microcephalic at birth. Deafness and ocular lesions were found in four patients, and congenital heart disease was found in three. All had abnormal ultrasonographic findings: linear-shaped hyperechogenicity over the basal ganglia was noted for five patients, periventricular punctate hyperechogenicity was noted for three, and subependymal cysts were observed in two. Follow-up ultrasonograms for two of the patients showed progressively enlarging hyperechogenic lesions. Calcification was found in both patients examined by means of computed tomography. All patients became microcephalic, with profound global developmental delay. Intracranial calcifications are common findings in patients with CRS. Ultrasonography should be performed for high-risk neonates, regardless of their symptoms. The finding of linear hyperechogenicity over the basal ganglia should prompt a search for all congenital infections, including CRS.

Secretion of active subtilisin YaB by a simultaneous expression of separate pre-pro and pre-mature polypeptides in Bacillus subtilis

Alkaline elastase YaB, produced by alkalophilic Bacillus YaB, is an extracellular serine protease having 55% homology to subtilisin BPN' and thus could be called subtilisin YaB. It is synthesized as a 378-amino acid preproenzyme and secreted into the culture medium as a 265-amino acid mature protease. To examine if the pro-peptide of subtilisin YaB functions in trans to guide the folding of secreted subtilisin YaB in vivo, we made genes encoding the pre-pro, pro and pre-mature portions and placed them under the control of the spac-1 promoter on a multi-copy plasmid. When simultaneous expression in Bacillus subtilis of both the pre-pro and pre-mature genes was induced with 0.5 mM isopropyl-1-thio-beta-D-galactopyranoside (IPTG), protease activity was detected in the medium. On the other hand, we could not detect protease activity when the expression of either the pre-mature gene alone or both the pro and pre-mature genes was induced. From these results, we concluded that the pro region functions in trans and outside the cells for the proper folding and activation of the enzyme.