Reduction of plasma glutamyl aminopeptidase activity in sporadic Alzheimer's disease

Previously, we hypothesized that aminopeptidase-catalyzed proteolysis may limit the rate of beta-amyloid catabolism in brain and that reduction of a certain aminopeptidase activity may lead to deposition of peptidic metabolites represented by beta-amyloid and thus to Alzheimer's disease (AD). To explore this possibility in clinical situations and to seek a possible biochemical marker for the disease, we quantitated four classes of aminopeptidase activities in cerebrospinal fluids and heparinized plasma from sporadic AD patients and agematched controls collected in two independent medical institutions. We found that only plasma glutamyl aminopeptidase activity was significantly and consistently lower in AD patients. Although the mechanism leading to such a biochemical change in plasma remains to be elucidated, the results provide support for the aminopeptidase hypothesis and indicate that the enzyme activity may potentially be used as a diagnostic/ predictive marker for AD.

High incidence of pneumonia in elderly patients with basal ganglia infarction

BACKGROUND

Pneumonia is a major cause of death in patients with cerebral infarction. We assessed morbidity associated with pneumonia in 276 patients 65 years of age or older who were admitted to a long-term care facility. Furthermore, we studied the swallowing reflex during the day and at night and monitored the occurrence of silent aspiration during sleep.

OBJECTIVES

To examine the possible relationship between the location of cerebral hemispheric infarctions and the incidence of pneumonia and to evaluate the role of silent aspiration in the development of pneumonia.

METHODS

The incidence of pneumonia was analyzed in 4 groups of patients who were assigned to a group on the basis of the following computed tomographic findings: no infarct (group A); 1 or more unilateral basal ganglia infarcts (group B); bilateral basal ganglia infarcts (group C); and 1 or more cerebral hemispheric infarcts outside the basal ganglia (group D). Criteria for diagnosis of pneumonia were (1) a new pulmonary infiltrate seen on a chest radiograph and (2) 1 or more of the following features: cough, temperature greater than 37.8 degrees C, or subjective dyspnea. Before the study, the patients with stroke were followed up for more than 1 year after their ictus and were monitored to determine if they sustained affecting cerebral hemispheric structures. The average duration of observation for incidence of pneumonia was 22 months. To study the swallowing reflex and to monitor for the occurrence of silent aspiration during sleep, 15 of the patients who were confined to bed or chair were randomly selected from each of groups A through C. The swallowing reflex was examined at both 1 PM and 1 AM and was evaluated according to latency of response, which was timed from the injection of 1 mL of distilled water into the pharynx through a nasal catheter to the onset of swallowing. The incidence of silent aspiration during sleep was examined using indium-111 chloride as a radioactive tracer attached to the teeth, and scanning of the thorax was performed the next morning.

RESULTS

The incidence of pneumonia was 2.12 times higher in the patients of group B (27.4%; P < .01) and 3.64 times higher in the patients of group C (47.0%; P < .001) than in the patients of group A (12.9%). The latency of response was longer in the patients of groups B (P < .05) and C (P < .001) than in those of group A at 1 AM. The percentage of positive scans was also higher in the patients of groups B (P < .01) and C (P < .001) than in those of group A.

CONCLUSION

Basal ganglia strokes might predispose these patients to develop pneumonia owing to frequent aspiration during sleep.

A magnetic resonance imaging study in first-episode disorganized-type patients with schizophrenia

Although a number of radiological studies have suggested that brains of patients suffering from schizophrenia have morphological abnormalities, the results are inconsistent. In the present study, in order to examine the brain, morphological features of homogeneous schizophrenics' brain magnetic resonance imagings (MRI) were taken, before neuroleptic treatment, from subjects suffering from disorganized-type schizophrenia, (DOS) during their first episodes. Results showed that DOS had significantly smaller indices for bilateral frontal gray matter (GM), left hippocampal formation (HF), left parahippocampal gray matter (PHGM) and left cingulate gyrus gray matter (CGM) than normal controls. These findings support the previous computed tomography (CT) and MRI studies on schizophrenic brains, although the subjects were not defined as disorganized-type, and may suggest the involvement of a neurocircuit between the bilateral frontal lobe and the left side of limbic system in the first-episode DOS group.

A case of neonatal choriocarcinoma

Choriocarcinoma occurring in a placenta and metastasizing to the fetus is quite rare. We describe here a case of such infantile choriocarcinoma, initially appeared as refractory anemia and rapidly metastasized to the liver, lungs, and brain. The placenta looked normal and was not submitted to histological examinations. Neither noninvasive nor invasive diagnostic methods (ultrasonography, computed tomography, magnetic resonance image, scintigraphy, and hepatic arteriography) gave any diagnostic information on the tumor. Liver biopsy was considered too risky due to a possible bleeding. Correct diagnosis was established only after the postmortem examination. Two months after the infant's death, we were informed that the mother was found having hepatic and pulmonary tumors. The importance of the maternal history and measurement of urinary human chorionic gonadotropin is emphasized for a rapid and correct diagnosis of infantile choriocarcinoma.

Working pressure for full balloon inflation during intraaortic balloon pumping

With changes in heart rate and mean aortic pressure, an intraaortic balloon (IAB) works with incomplete inflation. The effects of initial peak positive pressure and plateau holding positive pressure on IAB volume were investigated and minimum pressures necessary to inflate an IAB to a desired volume were established with a standard IAB catheter (Datascope type, 9.5 Fr, 40 ml). Initial peak pressure greater than 200 mm Hg was adequate to attain the desired volume of the IAB. Plateau positive pressure should be altered in accordance with hemodynamic changes.

Serine phospholipid-specific phospholipase A that is secreted from activated platelets. A new member of the lipase family

Rat platelets secrete two types of phospholipases upon stimulation; one is type II phospholipase A2 and the other is serine-phospholipid-selective phospholipase A. In the current study we purified serine-phospholipid-selective phospholipase A and cloned its cDNA. The final preparation, purified from extracellular medium of activated rat platelets, gave a 55-kDa protein band on SDS-polyacrylamide gel electrophoresis. [3H]Diisopropyl fluorophosphate, an inhibitor of the enzyme, labeled the 55-kDa protein, suggesting that this polypeptide possesses active serine residues. The cDNA for the enzyme was cloned from a rat megakaryocyte cDNA library. The predicted 456-amino acid sequence contains a putative short N-terminal signal sequence and a GXSXG sequence, which is a motif of an active serine residue of serine esterase. Amino acid sequence homology analysis revealed that the enzyme shares about 30% homology with mammalian lipases (lipoprotein lipase, hepatic lipase, and pancreatic lipase). Regions surrounding the putative active serine, histidine, and aspartic acid, which may form a "lipase triad," were highly conserved among these enzymes. The recombinant protein, which we expressed in Sf9 insect cells using the baculovirus system, hydrolyzed a fatty acyl residue at the sn-1 position of lysophosphatidylserine and phosphatidylserine, but did not appreciably hydrolyze phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidic acid, and triglyceride. The present enzyme, named phosphatidylserine-phospholipase A1, is the first phospholipase that exclusively hydrolyses the sn-1 position and has a strict head group specificity for the substrate.

Organization and differential expression of the human monocyte chemoattractant protein 1 receptor gene. Evidence for the role of the carboxyl-terminal tail in receptor trafficking

Two forms of the monocyte chemoattractant protein-1 receptors (the type A monocyte chemoattractant protein 1 (MCP-1) receptor CCR-2A and the type B MCP-1 receptor (CCR-2B) have been recently cloned and found to differ only in their terminal carboxyl tails. Here, we report that the two isoforms are alternatively spliced variants of a single MCP-1 receptor gene. Sequencing of the gene revealed that the 47-amino acid carboxyl tail of CCR2B was located in the same exon as the seven transmembrane domains of the receptor, and the 61-amino acid tail of CCR2A was in a downstream exon. Examination of freshly isolated human monocytes by reverse transcriptase-polymerase chain reaction revealed that CCR2B was the predominant isoform and that message levels of both CCR2A and CCR2B decreased as the monocytes differentiated into macrophages. In stably transfected cell lines, CCR2B trafficked well to the cell surface, but CCR2A was found predominantly in the cytoplasm. Equilibrium binding studies revealed that those CCR2A receptors that successfully trafficked to the cell surface bound MCP-1 with high affinity (Kd = 310 pM), similar to CCR2B. In signaling studies, both CCR2A and CCR2B mediated agonist-dependent calcium mobilization, as well as inhibition of adenylyl cyclase. Creation of chimeras between CCR2A and the human thrombin receptor revealed that the cytoplasmic retention of CCR2A was due to its terminal carboxyl tail. Progressive truncation of the carboxyl tail indicated that a cytoplasmic retention signal(s) was located between residues 316 and 349. These data indicate that the alternatively spliced form of the human MCP-1 receptor (CCR2A) binds MCP-1 with high affinity and is a functional receptor and that expression at the cell surface is controlled by amino acid sequences located in the terminal carboxyl tail.

Brain acetylhydrolase that inactivates platelet-activating factor is a G-protein-like trimer

The platelet-activating factor PAF (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a potent lipid first messenger active in general cell activation, fertilization, inflammatory and allergic reactions, asthma, HIV pathogenesis, carcinogenesis, and apoptosis. There is substantial evidence that PAF is involved in intracellular signalling, but the pathways are poorly understood. Inactivation of PAF is carried out by specific intra- and extracellular acetylhydrolases (PAF-AHs), a subfamily of phospholipases A2 that remove the sn-2 acetyl group. Mammalian brain contains at least three intracellular isoforms, of which PAF-AH(Ib) is the best characterized. This isoform contains a heterodimer of two homologous catalytic subunits alpha1 and alpha2, each of relative molecular mass 26K, and a non-catalytic 45K beta-subunit, a homologue of the beta-subunit of trimeric G proteins. We now report the crystal structure of the bovine alpha1 subunit of PAF-AH(Ib) at 1.7 A resolution in complex with a reaction product, acetate. The tertiary fold of this protein is closely reminiscent of that found in p21(ras) and other GTPases. The active site is made up of a trypsin-like triad of Ser 47, His 195 and Asp 192. Thus, the intact PAF-AH(Ib) molecule is an unusual G-protein-like (alpha1/alpha2)beta trimer.

Acute regulation by dietary phosphate of the sodium-dependent phosphate transporter (NaP(i)-2) in rat kidney

Alteration of the dietary intake of phosphate (P(i)) leads to rapid changes in renal P(i) transport activity. The present study, examined the underlying cellular mechanisms of the rapid regulation, with special reference to renal P(i) cotransporter. Rats were fed either a low-P(i) (0.02%) diet (CLP rats), the low-P(i) diet followed by a high-P(i) (1.2%) diet (AHP rats), or a normal (0.6%) diet (control rats). Na(+)-dependent P(i) transport activity in the brush border membrane was significantly increased in CLP rats compared with control rats, and this activity decreased rapidly within 2 h after the change of diet in AHP rats. Kinetic analysis of P(i) transport in the AHP rats indicated that the reduction was accompanied by a decrease in the apparent Vmax for Na(+)-dependent P(i) uptake. Northern blot analysis showed no difference in the abundance of NaP(i)-2 mRNA of the kidney between AHP and CLP rats. In contrast, Western blot analysis of renal brush border membrane proteins of AHP rats indicated a significant decrease in the abundance of NaP(i)-2 protein as compared with CLP rats. Immunoreactive signals for NaP(i)-2 were detected in lysosomal fractions of AHP and CLP rats. Immunohistochemical analysis showed that, NaP(i)-2 immunoreactivity in AHP rats was largely reduced in the apical membrane of the proximal tubular epithelial cells. Neither cycloheximide nor actinomycin D affected high-P(i)-induced reduction of NaP(i)-2 protein in the brush border membrane of AHP rats, indicating that de novo protein synthesis of an unidentified regulator protein was not involved in the mechanism of this reduction. In contrast, treatment with colchicine, which disrupts microtubulers, abolished the effect of high-P(i) diet on NaP(i)-2 expression. These results suggested that rapid endocytotic internalization of NaP(i)-2 may occur specifically in the brush border membrane following an acute increase in dietary P(i) intake.

Assessment of in vitro interleukin-2-producing capacity of peripheral blood lymphocytes from patients with periodontitis

In this cross-sectional study, we assessed the in vitro interleukin-2 (IL-2) producing capacity of peripheral blood mononuclear cells (PBMC) and lymphocytes from patients with different forms of periodontitis. 45 patients (12 with localised early onset periodontitis (LEOP), 20 with generalised early onset periodontitis (GEOP), and 13 with adult periodontitis (AP), and 20 periodontally healthy subjects (HS), participated in this study. PBMC and lymphocytes were isolated from the subjects and their cells were stimulated with an anti-CD3 monoclonal antibody (anti-CD3 MoAb) and the secreted IL-2 levels in the culture were bioassayed. No significant differences could be found in IL-2 producing activity of PBMC between the patients and HS group. There was wide interindividual variation and high and low "IL-2 producers" were noted. We found a LEOP patient who was a high producer of IL-2 (> mean + 8 SD) and 2 LEOP patients and a HS who were low producers of IL-2 (< mean - 1.5 SD) with their lymphocytes. Incidentally, the HS became a LEOP patient during 2 years after this study. The low IL-2 producing activity of their PBMC and lymphocytes against anti-CD3 MoAb could not be overcome by stimulation with phorbol myristate acetate and ionomycin. Thus, we found high and low IL-2 producing capacity by PBMC and lymphocytes in certain subjects and these subjects may be useful models in assessing the role of systemic IL-2 productivity associated with their progression of periodontal disease.

[Causative factors resulting in intractability of congenital hydrocephalus--analysis of psychomotor development and MRI findings of the brain in sixteen congenitally hydrocephalic patients]

Sixteen patients out of 58 children with congenital hydrocephalus were retrospectively investigated in terms of their psychomotor development and morphological findings of the brain by magnetic resonance imaging (MRI), and morphological backgrounds of the brain in patients affected by "intractable hydrocephalus" were intended to be clarified. The 16 patients were primarily diagnosed as having aqueductal stenosis or communicating hydrocephalus during the era before introduction of MRI. On the basis of the rate of head growth, sixteen patients were divided into three groups; group-1: overt neonatal hydrocephalus (5 cases) ; group-2: rapidly progressive hydrocephalus with normal head circumference at birth (5 cases); and group-3: slowly progressive hydrocephalus with its onset after the neonatal period (6 cases). Psychomotor development of the 16 cases was analyzed by using various methods including the Tanaka-Binet intelligence test and WISC-R. Four cases in group-1 and all cases in group-2 were found to have IQ or DQ below 50, while the other remaining cases were found to have IQ of 82 in group-1 (one case) and IQ ranging from 67 to 113 in group-3. MRI performed in those 9 cases with IQ below 50 revealed various morphological abnormalities of the brain. Those abnormalities were characterized by disturbance of organogenesis and/or histogenesis of the brain dating from the first 20 weeks of fetal life. It is strongly suggested that in the pathogenesis of intractable hydrocephalus developmental malformation of the brain occurring during the first 20 weeks of gestation are involved. Functional and morphological impairments of the brain possibly caused by progression of fetal hydrocephalus and delay of CSF diversion before and after birth seem important in the pathogenesis of intractable hydrocephalus.

Percentage changes in serum pepsinogens are useful as indices of eradication of Helicobacter pylori

OBJECTIVE

Eradication of Helicobacter pylori has been gaining significance for the treatment of gastroduodenal diseases. Establishment of a precise diagnostic method for H. pylori is of great value. The aim of this study was to establish a new method for precisely judging the eradication of this bacteria.

METHODS

We measured serum pepsinogen I (PG I) and pepsinogen II (PG II) levels in 105 cases of peptic ulcer with H. pylori infection before and after anti-H. pylori treatment, determined percentage changes in serum PG I:PG II ratios before and 1 month after the treatment, and established cut-off values for them to distinguish success from failure of H. pylori eradication. Cut-off values for percentage changes in serum PG I:PG II ratios were tentatively set as +40%, +25%, and +10% when the serum PG I:PG II ratios before treatment were less than 3.0, not less than 3.0 but less than 5.0, and not less than 5.0, respectively.

RESULTS

With these cut-off values, the sensitivity, specificity, and validity for determination of eradication of H. pylori-on the basis of culture, histology, the rapid urease test, and a polymerase chain reaction method-were 100.0%, 93.1%, and 96.2%, respectively. These cut-off values could be applied to both gastric ulcer and duodenal ulcer.

CONCLUSION

Our findings suggest that percentage changes in serum PG I:PG II ratios are useful as indices for distinguishing success from failure in eradication therapy for H. pylori.

Apolipoprotein E genotyping and cerebrospinal fluid tau protein: implications for the clinical diagnosis of Alzheimer's disease

Apolipoprotein E (ApoE) genotyping was conducted in sporadic Alzheimer's disease (AD, n = 91) as well as in other dementing disorders including Parkinson's disease (PD, n = 73), autopsy-confirmed diffuse Lewy body disease (DLBD, n = 16), progressive supranuclear palsy (n = 13), vascular dementia (n = 55), alcoholic dementia (n =25) and normal control subjects (n = 77). ApoE epsilon 4 allele frequency was significantly higher in AD (33.5%, p < 0.001), DLBD (40.6%, p < 0.001) and demented PD (29.4%, p < 0.05) compared to that in normal controls (11.7%). The association of the ApoE epsilon 4 allele with AD was more pronounced in early-onset AD (46.4%) than in late-onset AD (27.8%). 46% of the AD individuals developed AD without association to ApoE epsilon 4, and epsilon 4 homozygotes were found not only in AD, but also in many of other dementing disorders. These results suggest that ApoE genotyping cannot provide certainty about the presence of absence of AD, and that it should be used as an adjunct to other diagnostic tests for AD. On the other hand, cerebrospinal fluid (CSF) tau levels were significantly elevated (p < 0.0001) in AD (78.0 +/- 44.2 pg/ml) compared to those in normal controls (10.6 +/- 8.6 pg/ml). The specificity and the sensitivity of distinguishing AD from normal controls was 95.0 and 91.2%, respectively. Elevated CSF-tau levels were also detected in some patients with acute neurological diseases including meningoencephalitis, Creutzfeld-Jacob disease, normal pressure hydrocephalus and vitamin B12 deficiency encephalopathy. Increased CSF-tau levels in AD were found regardless of the age at onset, clinical stage, ApoE genotype, alpha 1-antichymotrypsin genotype, and presenilin-1 genotype. The CSF-tau levels continued to be abnormal during the progression of AD. These results suggest that CSF-tau serves as an unequivocal and reliable biological marker to aid in the clinical diagnosis of AD.

Gene cluster for dissimilatory nitrite reductase (nir) from Pseudomonas aeruginosa: sequencing and identification of a locus for heme d1 biosynthesis

The primary structure of an nir gene cluster necessary for production of active dissimilatory nitrite reductase was determined from Pseudomonas aeruginosa. Seven open reading frames, designated nirDLGHJEN, were identified downstream of the previously reported nirSMCF genes. From nirS through nirN, the stop codon of one gene and the start codon of the next gene were closely linked, suggesting that nirSMCFDLGHJEN are expressed from a promoter which regulates the transcription of nirSM. The amino acid sequences deduced from the nirDLGH genes were homologous to each other. A gene, designated nirJ, which encodes a protein of 387 amino acids, showed partial identity with each of the nirDLGH genes. The nirE gene encodes a protein of 279 amino acids homologous to S-adenosyl-L-methionine:uroporphyrinogen III methyltransferase from other bacterial strains. In addition, NirE shows 21.0% identity with NirF in the N-terminal 100-amino-acid residues. A gene, designated nirN, encodes a protein of 493 amino acids with a conserved binding motif for heme c (CXXCH) and a typical N-terminal signal sequence for membrane translocation. The derived NirN protein shows 23.9% identity with nitrite reductase (NirS). Insertional mutation and complementation analyses showed that all of the nirFDLGHJE genes were necessary for the biosynthesis of heme d1.

Graves' disease associated with exophthalmos, cerebral ventricular dilatation and accelerated growth

A report is presented of a girl with Graves' disease, which was diagnosed at the age of 1.7 years. The mother had no thyroid disease. The patient developed signs of hyperthyroidism shortly before her first birthday, and the most prominent manifestations were accelerated skeletal maturation and linear growth, and dilatation of the brain ventricles. The latter manifestation, which has not been reported previously, was reversible upon normalisation of thyroid function with antithyroid treatment for three years.

cDNA cloning and expression of intracellular platelet-activating factor (PAF) acetylhydrolase II. Its homology with plasma PAF acetylhydrolase

Platelet-activating factor (PAF) acetylhydrolase, which inactivates PAF by removing the acetyl group at the sn-2 position, is widely distributed in plasma and tissues. We previously demonstrated that tissue cytosol contains at least two types of PAF acetylhydrolase, isoforms Ib and II, and that isoform Ib is a heterotrimer comprising 45-, 30-, and 29-kDa subunits, whereas isoform II is a 40-kDa monomer. In this study, we isolated cDNA clones of bovine and human PAF acetylhydrolase isoform II. From the longest open reading frame of the cloned cDNAs, both bovine and human PAF acetylhydrolases II are predicted to contain 392 amino acid residues and to exhibit 88% identity with each other at the amino acid level. Both enzymes contain a Gly-X-Ser-X-Gly motif that is characteristic of lipases and serine esterases. Expression of isoform II cDNA in COS7 cells resulted in a marked increase in PAF acetylhydrolase activity. An immunoblot study using an established monoclonal antibody against the bovine enzyme revealed that the recombinant protein exists in the membranous fraction as well as the soluble fraction. Isoform II is expressed most abundantly in the liver and kidney in cattle, but low levels were also observed in other tissues. The amino acid sequence deduced from the cDNA of isoform II had no homology with any subunit of isoform Ib. Interestingly, however, the amino acid sequence of isoform II showed 41% identity with that of plasma PAF acetylhydrolase. Combined with previous data demonstrating that isoform II shows similar substrate specificity to plasma PAF acetylhydrolase, these results indicate that tissue type isoform II and the plasma enzyme may share a common physiologic function.

Platelet-activating factor acetylhydrolase expression and activity suggest a link between neuronal migration and platelet-activating factor

A hemizygous deletion of LIS1, the gene encoding alphaLis1 protein, causes Miller-Dieker syndrome (MDS). MDS is a developmental disorder characterized by neuronal migration defects resulting in a disorganization of the cerebral and cerebellar cortices. alphaLis1 binds to two other proteins (beta and gamma) to form a heterotrimeric cytosolic enzyme which hydrolyzes platelet-activating factor (PAF). The existence of heterotrimers is implicated from copurification and crosslinking studies carried out in vitro. To determine whether such a heterotrimeric complex could be present in tissues, we have investigated whether the alphaLis1, beta, and gamma genes are coexpressed in the developing and adult brain. We have isolated murine cDNAs and show by in situ hybridization that in developing brain tissues alphaLis1, beta, and gamma genes are coexpressed. This suggests that alphaLis1, beta, and gamma gene products form heterotrimers in developing neuronal tissues. In the adult brain, alphaLis1 and beta mRNAs continue to be coexpressed at high levels while gamma gene expression is greatly diminished. This reduction in gamma transcript levels is likely to result in a decline of the cellular concentration of alphaLis1, beta, and gamma heterotrimers. The developmental expression pattern of alphaLis1, beta, and gamma genes is consistent with the neuronal migration defects seen in MDS; regions containing migrating neurons such as the developing cerebral and cerebellar cortices express these genes at a particularly high level. Furthermore, we uncovered a correlation between gamma gene expression, granule cell migration, and PAF hydrolytic activity in the cerebellum. In this tissue gamma gene expression and PAF hydrolysis peaked at Postnatal Days P5 and P15, a period during which neuronal migration in the cerebellum is most extensive. Mechanisms by which PAF could affect neuronal migration are discussed.

The apolipoprotein E gene in Binswanger's disease and vascular dementia

We investigated the polymorphism of the apolipoprotein E (ApoE) gene using a PCR-RFLP method in patients with Binswanger's disease (BD), non-BD vascular dementia, or Alzheimer's disease (AD). The frequency of the epsilon 4 allele of the ApoE (ApoE4) in BD patients and non-BD vascular dementia patients did not differ from that observed in the nondemented elderly controls, but it was significantly lower than the frequency in AD patients. These results and other recent observations suggest that one or more factors other than the ApoE gene contribute to the pathogenesis of dementia in BD and non-BD vascular dementia.

[The present state of the 24-hour care system of our hospital and the examination of the significance and problems of the system]

The wishes of patients with terminal cancer are often not realized even if they indicate they want to die at home. We introduced a 24-hour visiting care system from November, 1994, with a view to making it possible for the patient who wants to to stay at home. As a result, the rate of the death at home increased; thus, the 24-hour visiting care system was significant for terminal care at home. On the other hand, from the viewpoint of a medical institution, the lack of sufficient cooperation with doctors and the increase of the burden on the staff were pointed out as problems to be resolved.

No association between c-fos gene polymorphisms and sporadic Alzheimer's disease

Although ApoE epsilon 4 is a major risk factor for sporadic Alzheimer's disease (AD), 20-30% of sporadic AD patients do not have this allele. This indicates that other risk factors are involved in the pathogenesis of sporadic AD. Studies of the genetic association between AD and polymorphisms in the c-fos gene, a candidate gene for AD, were conducted. The polymorphisms of DsaI in exon 2 and Sau3 AI in intron 2 were examined in 89 patients diagnosed as sporadic cases of probable AD clinically and radiologically according to the NINCDS-ADRDA criteria. This was also undertaken in 96 controls. There was no significant difference between the groups in allele frequencies or genotype counts. Although c-fos gene as a locus conferring susceptibility to sporadic AD cannot be ruled out, these data could not support the hypothesis that a c-fos allele should be another risk factor for sporadic AD.

Lateral approach to intraorbital lesions: anatomic and surgical considerations

OBJECTIVE

We present our microsurgical lateral orbital approach for intraorbital lesions, with special emphasis on the microanatomy of the orbit.

METHODS

Among 26 patients, such lesions included tumors of the lacrimal glands, cavernous angioma, meningioma, neuroma, and other tumors. These intraorbital lesions were removed through a 35- to 40-mm lateral skin incision, and this was followed by lateral orbitotomy featuring a microsurgical dissecting technique. If it was necessary to gain access to the deep lateral portion of the muscle cone, the lateral orbitotomy was extended to the anterior temporal dura. There are two microsurgical routes into the muscle cone, one above and the other below the lateral rectus muscle. The structures encountered along these two routes were demonstrated in an anatomic study of the orbit in cadavers.

RESULTS

Lesions located in the lateral compartment of the orbit could be exposed through lateral orbitotomy and were completely removed in most cases. Complications in our series of 26 patients included one case of postoperative visual impairment, one case of tonic pupil, and three cases of transient impairment of eye movement.

CONCLUSION

We think that, with an intimate understanding of the anatomy of the orbit, intraorbital lesions located in the lateral compartment of the orbit, and even those in the lateral apex, can be safely removed through lateral orbitotomy.

Arachnoid cysts of the middle cranial fossa: experience with 77 patients who were treated with cystoperitoneal shunting

OBJECTIVE

Our surgical results of middle fossa arachnoid cysts are presented, and advantages and disadvantages of cystoperitoneal shunting are discussed.

METHODS

Seventy-seven patients with middle fossa arachnoid cysts, including 20 cases of asymptomatic cyst, were treated by cystoperitoneal shunting. In cases associated with subdural hematoma, the cystoperitoneal shunt was preceded by irrigation of the hematoma. Follow-up periods ranged from 8 months to 16 years (mean, 7.7 yr).

RESULTS

In all cases, postoperative computed tomography and magnetic resonance imaging revealed subsequent expansion of the surrounding brain, concomitant with either the disappearance of or a marked decrease in the size of the cyst. Patients who initially presented with headaches, hemiparesis, choked discs, and diplopia were cured postoperatively. Head enlargement presented preoperatively did not progress after shunting. Mental retardation and behavior problems, however, remained unchanged postoperatively, even though the cyst had disappeared. One cystoperitoneal shunt became infected, and shunt malfunction developed in eight patients. Four of the eight patients presented acute signs and symptoms of intracranial hypertension when the shunt malfunctioned, although the concurrent increase in cyst size was slight and ventriculomegaly was not seen. The observed condition in these four patients could be considered shunt dependency.

CONCLUSION

Cystoperitoneal shunting is a valid method of achieving obliteration of the cyst and clinical improvement and seems to feature low operative risk and few complications. It should be noted, however, that some patients experience shunt dependency after cystoperitoneal shunting.