Isolation, Characterization, and Distribution of a Biocontrol Fungus from Cysts of Heterodera glycines

ABSTRACT Seventy-six populations of Heterodera glycines were collected from 33 counties in 10 states of the United States along the Mississippi and Missouri Rivers in 1992 and 1993. A sterile hyphomycete fungus of an unnamed taxon, designated ARF18 and shown to be a parasite of eggs of H. glycines, was isolated from eggs and cysts of 10 of the populations from Kentucky, Louisiana, Mississippi, and Tennessee. Ten isolates of ARF18 obtained in this study and seven isolates obtained in earlier studies were characterized for cultural morphology on several growth media, the ability to produce sclerotium-like structures (SLS) on cornmeal agar, growth rates, pathogenicity to eggs of H. glycines in vitro, and mitochondrial (mt) DNA restriction fragment length polymorphisms (RFLPs). All 17 isolates of ARF18 readily grew on potato dextrose agar, cornmeal agar, and nutrient agar. Based on colony morphology and SLS appearance on cornmeal agar, the isolates could be grouped into two morphological phenotypes. Isolates that produced SLS that were composed of a compact mass of hyphae were designated ARF18-C, whereas isolates that produced SLS composed of a mass of loosely clumped hyphae were designated ARF18-L. Only minor differences in growth rates were detected among the ARF18-C and ARF18-L isolates. All 10 ARF18-C isolates, which were from Arkansas, Louisiana, Mississippi, and Tennessee, belonged to a single mtDNA RFLP haplotype. The seven ARF18-L isolates shared many comigrating mtDNA restriction fragments with one another, but belonged to three distinct mtDNA RFLP haplotypes. Ability to infect eggs of H. glycines in vitro varied considerably among the various isolates of ARF18. In particular, several of the ARF18-C isolates were consistently able to infect over 50% (mean = 70.0%, standard deviation = 16%) of the eggs of H. glycines, whereas ARF18-L infected eggs to a lesser degree (mean = 25%, standard deviation = 27%). ARF18-C was isolated only from H. glycines populations from below 37 degrees N latitude. The presence of ARF18 was associated with soils with Mg levels <314 kg/ha, cyst numbers >4.5 per 100 cm(3), and iron levels >203.5 kg/ha; or with Mg levels >314 kg/ha and Na levels <121 kg/ha. The widespread distribution of ARF18 and the ability of some isolates to aggressively colonize eggs of H. glycines are indications that it has potential as a biological control agent for H. glycines.

Technetium-99m-ECD brain SPECT in cerebral palsy: comparison with MRI

Hypoxic brain injury is one of the major causes of cerebral palsy. Therefore, this study was performed to evaluate cerebral perfusion impairments in these patients using 99mTc-ECD brain SPECT.

METHODS

Fifty-one patients (31 boys, 20 girls; age range 6 mo to 6 yr, 11 mo) with clinical manifestations of cerebral palsy underwent brain SPECT after intravenous injection of 99mTc-ECD. The clinical subtypes of cerebral palsy were spastic diplegia (n = 35), spastic quadriplegia (n = 11), spastic hemiparesis (n = 2), choreoathetoid (n = 2) and mixed (n = 1). Transaxial, coronal and sagittal images obtained with a brain-dedicated annular crystal gamma camera were qualitatively analyzed and compared with the findings of magnetic resonance imaging (MRI).

RESULTS

In SPECT, thalamic hypoperfusion was seen in all patients except one (98%), followed by hypoperfusion in the temporal lobe (52.9%, n = 27), basal ganglia (41.2%, n = 21), cerebellum (39.2%, n = 20) and extratemporal cortices (21.6%, n = 11). However, MR imaging demonstrated thalamic abnormality in seven (13.7%), basal ganglia in two (3.9%), extratemporal cortical defect in five (9.8%) and cerebellar atrophy in one (1.9%). Instead, white matter changes such as periventricular leukomalacia or ischemia (56.9%, n = 25) and thinning of corpus callosum (49%, n = 25) were the major findings.

CONCLUSION

Brain SPECT is useful in the diagnosis of cerebral palsy and is more sensitive in the detection of cortical, subcortical nuclei and cerebellar abnormalities. MRI is superior in the detection of white matter changes.

Mixed tumour of schwannoma and meningioma components in a patient with NF-2

The authors present the case of an intracranial tumour consisting of both schwannoma and meningioma within the same tumour, in a patient with neurofibromatosis-2 (NF-2). A pre-operative diagnosis of this mixed tumour was not made. However, retrospectively, a meningiomatous area was found inside the acoustic neurinoma on magnetic resonance (MR) images. Predominant schwannoma with a minor component of meningioma was confirmed by histopathological and immunohistochemical examinations. The transitional zones of these two different tumours were macroscopically sharp but microscopically interdigitated. The patient had another meningioma and schwannoma in a separate section of the cranial cavity. Based on this patient, it is suggested that the collision of two kinds of tumours is the most likely hypothesis to explain the development of mixed components of schwannoma and meningioma within the same tumour.

Pineal tumors: experience with 48 cases over 10 years

The authors retrospectively reviewed 48 patients treated at Seoul National University Hospital (SNUH) between 1986 and 1995. There were 35 children and 13 adults, accounting for 10.1% of 345 pediatric and 0.68% of 1914 adult brain tumors in SNUH during the same period. The 48 cases consisted of 33 cases of germ cell tumor (69%, GCT); 6 of pineoblastoma (PB, 12.5%); 3 of pineocytoma (PC, 6.3%); 3 of anaplastic astrocytoma (6.3%); 1 of astrocytoma; 1 of glioblastoma; and 1 of ependymoma. The median age was 13 years (range 1-59) and the male-to-female ratio was 3.36:1. The most frequent presenting symptom was due to increased intracranial pressure (90%), followed by Parinaud syndrome or diplopia (50%). Patients with a benign tumor, such as teratoma (TE), astrocytoma, or ependymoma, underwent surgery by the occipital transtentorial approach (OTT) for attempted radical resection without adjuvant therapy, while patients with immature teratoma (imTE), PC, and anaplastic astrocytoma underwent regional radiotherapy (RT) after debulking via OTT. Seven patients with nongerminomatous malignant GCT (NG-MGCT) and 3 with germinoma (GE) underwent craniospinal radiation only, 6 with GE, a NG-MGCT, and 2 with GE+TE received craniospinal radiotherapy (CSRT) after debulking via OTT. Three patients with GE, 4 with NG-MGCT, and 3 with PB underwent radiochemotherapy after debulking via OTT. Forty-four patients were followed up after treatment. The median follow-up period was 36 months. All patients with GE were alive after RT at 36 months (median) of follow-up (range 7-70 months). All with GE+TE and TE were alive. Three patients with PC or astrocytoma were also alive with stable or no evidence of disease. In 1 of the 3 cases of imTE there was a recurrence. However, 4 patients with NG-MGCT died, all of whom had undergone CSRT only; 2 PB patients were alive (12, 19 months), 1 in a moribund status (36 months), and 2 were dead (6, 60 months). The overall mean survival time with pineal tumors was 66 months and the 3-year survival rate was 84% with minimal posttreatment complications. It is concluded that pineal region tumors have male and childhood predominances, and the most common tumor is GCT. The majority of pineal region tumors are malignant. Pineal region tumors can be approached safely and effectively and the surgical complications are mostly transient. Their prognosis is dependent on the pathologies and treatment modalities.

Phylogenetic analysis of the nef gene reveals a distinctive monophyletic clade in Korean HIV-1 cases

To study the genetic variation of the HIV-1 strains prevalent in South Korea, we analyzed the nef sequences derived from 46 HIV-1-positive individuals living in various geographic regions in Korea. Phylogenetic analysis revealed four subtypes of HIV-1: A (3 patients), B (41 patients), D (1 patient), and a type that could not be clearly classified to any known subtype (1 patient). Thirty-five of the 41 Korean subtype B isolates formed a distinct monophyletic clade that is not related to any of the international sequences from the Los Alamos Database or GenBank as of June 1997. Indeed, the presence of unique conserved sequences was identified among the Korean isolates in this Korean subtype B group. The variations in the nucleotide sequences of a majority (32 of 35) subtype B samples within the Korean clade were 1.9% to 8.8%, and amino acid sequences varied from 3.9% to 15.5%. These results suggest that HIV-1 strains currently present in South Korea might have originated from a few sources or might be developing through a certain selective pressure. This is the first report on the molecular nature of the HIV-1 infection present in South Korea.

Large glial cyst of the pineal gland: a possible growth mechanism. Case report

The authors report on a patient who presented with a large symptomatic glial cyst of the pineal gland communicating with the third ventricle. The hole between the ventricle and the cyst, suspected on magnetic resonance images, was found at surgery. The to-and-fro flow mechanism is considered to be involved in the pathogenesis of growth in this unusual large glial cyst of the pineal gland, although this mechanism cannot be applied universally.

Dicistronic tagging of genes active in embryonic stem cells of mice

A gene-trap vector, pWH14, has been developed to tag genes expressed in embryonic stem (ES) cells of the mouse. The approach relies on the ability of the endogenous promoter to drive promoterless neo-IRES-lacZ construct producing a dicistronic mRNA consisting of the neomycin-resistance (neo) gene and the beta-galactosidase gene sequence. The neo gene produces a chimeric protein with the truncated product of the tagged gene and serves as a selectable marker for an insertion into an expressed gene. The internal ribosome entry site (IRES) sequence from murine encephalomyocarditis virus allows the translation of the second cistron, lacZ, to produce beta-galactosidase that can be used as a reporter for the expression of the tagged gene. The pWH14 vector was introduced into ES cells by electroporation, and the cells were selected for G418-resistance. About 50% of the G418-resistant colonies were stained positive for the beta-galactosidase activity. Southern analysis showed that each clone had one or more vector sequences integrated. Northern blot analysis of the clones positive for beta-galactosidase indicated that the fused RNAs containing the neo and the beta-gal genes were derived from the endogenous promoters of the tagged genes. Seven clones were chosen and injected into blastocysts, and chimeras were obtained. Two of the gene-trap insertions (wh14.1 and wh14.3) were transmitted through germ-line. In these two lines, the pattern of lacZ expression was restricted to early stages of embryos. This gene-trap vector may provide a means for tagging and studying the active genes in vivo in early embryogenesis.

Distribution of Races of Heterodera glycines in the Central United States

A total of 62 populations of Heterodera glycines were collected in 10 states along the Mississippi and Missouri rivers, and 206 populations were collected in Arkansas. Among the 62 populations, races 2, 3, 4, 5, 6, 9, and 14 were found south of 37 degrees N latitude, and races 1 and 3 were found north of 37 degrees N latitude. In Arkansas samples, races 2, 4, 5, 6, 9, and 14 comprised 87% of the populations. In both groups of samples, H. glycines populations with genes that enabled the population to parasitize cv. Pickett occurred the most frequently, followed by those with genes for parasitism of cv. Peking, then PI88.788, and the fewest with genes for parasitism of PI90.763. The diversity of races in this study raises questions about the effectiveness of race-specific cultivars for the management of soybean cyst nematodes. The greater diversity of races of H. glycines in the southern United States may be because of a longer history of planting resistant cultivars.

Central neurocytoma: the role of radiation therapy and long term outcome

BACKGROUND

It has been suggested that the biologic behavior of central neurocytoma is indolent, although little is known regarding the role of radiation therapy and long term outcome. To clarify the role of radiation therapy and long term outcome, the authors retrospectively analyzed 15 cases of central neurocytoma.

METHODS

Clinical records and radiologic findings of 15 cases of central neurocytoma diagnosed at Seoul National University Hospital between January 1982 and February 1995 were carefully reviewed. The duration of follow-up was from 18-168 months (mean, 52 months); follow-up images were reviewed and the patient's Karnofsky performance scale (KPS) was assessed up to the time of last follow-up.

RESULTS

The age of the patients ranged from 15 to 60 years (mean, 25 years) and the male to female ratio was 11:4. Macroscopic total resection of the tumor was performed in seven patients, two of whom received fractionated radiation therapy. Subtotal removal of the tumor was performed in eight patients, five of whom received this same therapy. In 2 of the 5 patients who did not receive radiation therapy after macroscopic total resection, the tumors recurred 8 and 21 months after surgery, respectively; in contrast, recurrence was not detected in the 2 patients who received fractionated radiation therapy after macroscopic total resection. In all five patients who received fractionated radiation therapy after subtotal resection, the tumor shrank (n = 3) or disappeared (n = 2) during the postsurgical follow-up period ranging from 27-113 months; the tumor began to shrink from 6 months to 2 years after radiation. No change was found in the three patients who did not receive radiation therapy after subtotal resection. At the time of last follow-up, the KPS was greater than 90 in all patients except one who required assistance in his daily activities because of complications from radiation therapy.

CONCLUSIONS

It is suggested that even if the biologic behavior of a central neurocytoma is benign, radiation therapy appears to have an effect on tumor control. However, it should be carefully decided whether to use radiation therapy for a residual tumor because radiation can cause delayed complications and the clinical course of subtotally resected patients who do not receive radiation therapy is extremely benign.

NF-kappaB-dependent expression of nitric oxide synthase is required for membrane fusion of chick embryonic myoblasts

The activity of nitric oxide synthase (NOS) has recently been shown to increase transiently but dramatically in chick embryonic myoblasts that are competent for fusion and that NO acts as a messenger for the cell fusion. Here we show that the rise in NOS activity is tightly correlated with an increase in NOS protein level, and its synthesis is under transcriptional control. In addition, a partial cDNA sequence of NOS obtained by reverse transcription PCR on total RNA from chick myoblasts was found to be identical with that of the inducible type of NOS (iNOS) from chick macrophage. Thus chick myoblast NOS must belong to the family of iNOS. Consistently, pyrrolidine dithiocarbamate, a potent inhibitor of nuclear factor kappaB (NF-kappaB), prevented the expression of myoblast NOS. Furthermore the antioxidant also strongly inhibited cell fusion, and its inhibitory effect was reversed by treatment with sodium nitroprusside, an NO-generating agent. In addition, nuclear extracts obtained from myoblasts that were competent for fusion, but not those from proliferating cells or from fully differentiated myotubes, were capable of binding to the consensus NF-kappaB site in the promoter region of the gene encoding iNOS. These results suggest that NF-kappaB-dependent expression of NOS is an important step in membrane fusion of chick embryonic myoblasts.

Differences in immunophenotyping of mucosal lymphocytes between ulcerative colitis and Crohn's disease

OBJECTIVES

Immunologic studies have characterized the numbers and types of inflammatory cells in diseased inflammatory bowel disease (IBD) mucosa but have yielded conflicting results regarding intestinal lymphocytes activation in IBD. We investigated the levels of lymphocytes subsets, interleukin-2 receptor, transferrin receptor, and T cell receptors in mainly isolated lamina propria lymphocytes. Including intraepithelial lymphocytes of normal colonic mucosa or IBD (ulcerative colitis and Crohn's disease) mucosa to understand the pathogenesis of IBD. We have results from this study.

RESULTS

1) In comparing ulcerative colitis with control, IL-2R (p < 0.05), TR (p < 0.01), and CD3/HLA-DR (< 0.05) showed a significant increase. 2) In comparing Crohn's disease with control, CD3 (P < 0.05), TCR alpha/beta (p < 0.01) and TCR gamma/delta (p < 0.05) showed a significant decrease. 3) In comparing Crohn's disease with ulcerative colitis, CD19 (p < 0.01), TR (p < 0.01), TCR alpha/beta (p < 0.01) and TCR gamma/delta (p < 0.05) showed a significant decrease.

CONCLUSION

From these results, there are increased T cell markers, IL-2R, TR, and CD3/HLA-DR in UC, but differently, decreased CD3, TCR alpha/beta and TCR gamma/delta in CD compared with control. In addition, definitive differences in lymphocytes markers, CD19, TR, TCR alpha/beta and TCR gamma/delta, which are higher in UC than in CD, may elucidate the different immunopathogenesis between UC and CD.

Cerebral sparganosis: clinical manifestations, treatment, and outcome

Cerebral sparganosis is a rare parasitic disease caused by infestation by the plerocercoid larva of Spirometra mansoni. The authors retrospectively analyzed 17 cases of cerebral sparganosis treated at Seoul National University Hospital between 1986 and 1994. The patients' ages at diagnosis ranged from 6 to 57 years (median 32 years) and the male/female ratio was 13:4. Diagnosis was based on radiological findings, serological test results, operative findings, and histopathological examinations. Characteristic magnetic resonance (MR) findings consisted of widespread white matter degeneration and cortical atrophy, mixed-signal lesion (low in the central and high in the peripheral regions on T2-weighted images) with irregular dense enhancement of central foci and changes in the location and shape of the enhancing lesion in follow-up studies. Ten patients underwent surgical removal of the parasitic lesion, six received medical treatment alone (five with praziquantel and one with antiepileptic drugs), and one underwent insertion of a ventriculoperitoneal shunt and a course of praziquantel. Follow-up periods ranged from 13 to 111 months (mean 49 months). Seven patients who underwent complete removal of the lesion, live worm, or degenerative worm with surrounding granuloma showed a favorable course. Patients who received medical treatment alone or incomplete removal exhibited progression in their neurological deficits and their seizures could not be controlled. Medication with praziquantel seemed to have no killing effect on live worms. The authors conclude that MR imaging is the most valuable modality for the early detection of cerebral sparganosis and that complete surgical removal of granuloma together with worms, whether they are alive or degenerative, is the treatment of choice.

The cholecystokinin receptor antagonist L-364,718 reduces taurocholate-induced pancreatitis in rats

CONCLUSION

Our results suggest that the cholecystokinin (CCK) receptor antagonist L-364,718 has a protective effect on taurocholate-induced pancreatitis, and thus, it is inferred that CCK may have a significant pathophysiological role in the early phase of pancreatitis.

BACKGROUND

Conflicting results have been obtained from studies designed to determine the role of CCK in the initial stages of pancreatitis.

METHODS

We evaluated the protective effect of the CCK receptor antagonist L-364,718 (devazepide) and of the trypsin inhibitor camostat, on taurocholate-induced pancreatitis in rats. L-364,718 (1 mg/kg) or camostat (200 mg/kg) was administered intragastrically 30 min before the induction of pancreatitis.

RESULTS

Infusion of sodium taurocholate (50 mg/kg) into the pancreaticobiliary duct caused severe pancreatitis with marked hyperamylasemia and reduction of tissue enzyme content at 12 h postinfusion. Pretreatment with L-364,718, but not with camostat, caused significant improvement in signs of experimental pancreatitis based on tissue enzyme content and morphology. Compared with untreated pancreatitis, there was relatively well-preserved lobular architecture, less edema, less infiltration of inflammatory cells, and more zymogen granules after L-364,718 pretreatment. Moreover, the reduction of enzyme content owing to pancreatitis was ameliorated by L-364,718 pretreatment.

Apoptosis induced by retinoic acid in Hep 3B cells in vitro

Human hepatoma Hep 3B cells underwent apoptosis in response to 100 microM all-trans retinoic acid (RA) in full serum (10% fetal calf serum) condition in vitro. Cell death began approximately 24 h following treatment, with more than 80% of the cells dead after 60 h. The dead cells, mainly detached cells, exhibited condensed chromatin and DNA fragmentation, which are indicative of endonuclease activation and are the hallmarks of apoptosis in epithelial cells. Concurrent exposure to 1 microM cycloheximide (CX) prevented approximately 50% of cell death and DNA fragmentation induced by RA. Thus, other toxic injury to the cells as well as apoptosis might be involved in cell death. Sixty hours exposure of RA decreased the percentage of cells in G1 phase (16.3 +/- 0.4% versus 52.4 +/- 2.1%; P < or = 0.01) and in G2/M phase (13.4 +/- 1.2% versus 21.2 +/- 0.7%; P < or = 0.01), but did not change percent of cells in S phase (20.8 +/- 0.2% versus 20.7 +/- 0.5%) of the cell cycle compared with control. RA may have caused accumulation of Hep 3B cells before G1 phase, and that G0/G1 transition is a main check point in the active process of apoptosis. Electron micrographs of the cells treated with RA revealed typical morphologic changes of apoptosis, besides toxic injury to the cells. These data strongly indicate that RA is able to induce apoptosis and the induction of apoptosis may contribute to the antitumor activity of RA against hepatoma cells.

Central neurocytoma: proliferative potential and biological behavior

The authors analyzed 13 central neurocytomas diagnosed at Seoul National University Hospital between January 1982 and December 1993 to clarify the proliferative potential and biological behavior of these tumors. The tumor was confined to the lateral and third ventricles in 12 cases and in one case extended from the posterior thalamus to the body and trigone area of the lateral ventricle. In all 13 cases, typical clinical and radiological findings were observed, and histological diagnosis was performed via craniotomy. The diagnosis was made using light microscopic examination, immunohistochemical staining for neuronal markers, and electron microscopic findings of neuronal differentiation. One patient died due to tumor progression with recurrence 26 months after subtotal removal plus radiation therapy. Another patient had a recurrence 18 months after total tumor removal. The remaining 11 patients are free of recurrent tumor after a follow-up period that ranged from 14 to 109 months (median 50 months). To predict the proliferative potential, immunoreactivity to proliferating cell nuclear antigen (PCNA), silver colloid staining for nucleolar organizing regions (AgNORs), and DNA flow cytometry were performed in 10 of the 13 cases. The proportion of PCNA-positive cells was less than 1% in all cases and the AgNORs score ranged from 1.11 to 2.0 (mean 1.67). The DNA flow cytometry revealed diploidy in all cases and the calculated proliferation index ranged from 5.1% to 9.6% (mean 7.8%). The one case of tumor recurrence, in which the authors performed the study of proliferative potential, and another case that demonstrated mild nuclear pleomorphism also showed low percentages of PCNA-positive cells, low AgNORs scores, and diploidy in DNA flow cytometry. It is suggested that most central neurocytomas follow a benign clinical course with low proliferative potential assessed by PCNA, AgNORs, and DNA flow cytometry; however, recurrence is possible within a relatively short time period.

Primary central nervous system lymphoma: variety of clinical manifestations and survival

A retrospective analysis of 23 non-immune compromised patients with primary central nervous system lymphoma (PCNSL) is reported. The patients consist of 14 males and 9 females and the median age is 50 years. Most patients presented with focal neurological deficits or symptoms of increased intracranial pressure (ICP) due to mass effects around the periventricular area. However, there were four cases of diffuse type, one case of intramedullary tumour, and four cases with rapid disease progression. All the patients underwent histological confirmation by craniotomy (16 cases) or stereotactic biopsy (7 cases). The radiation therapy started after histological diagnosis in all and 6 cases received additional chemotherapy. The median survival after diagnosis of overall patients was 23 months. Six patients are in disease free status at a mean of 35 months follow-up. The uni- and multi-variative risk analysis revealed five favourable factors on survival: (1) age less than 60 years (0.05 < p < 0.1); (2)pre-operative Karnofsky performance scale (KPS) > or = 70 (p < 0.05); (3) symptom duration over four weeks (p < 0.05); (4) radiation dosage > or = 5500 cGy (p < 0.05); (5)absence of malignant cells in cerebrospinal fluid (CSF) (p < 0.05). The most frequent site of recurrence was the local area as shown in seven cases out of 11 recurrent cases. But six patients had diffuse recurrence (4 cases), systemic recurrence (2 cases), and drop metastasis (1 case). Although the recurred PCNSL had rapid progression and a grave prognosis, aggressive treatment prolonged the postrecurrence survival time significantly. Our experience suggests that 1) there are various clinical and radiological presentations and progressions of the disease; 2) treatment method should be decided along with the clinical presentation, progression of disease, and prognostic factors; 3) early diagnosis and early detection of recurrence enable the start of definitive treatment when the medical condition is still satisfactory.

Efficacy of the Nematophagous Fungus ARF18 in Alginate-clay Pellet Formulations Against Heterodera glycines

Dry alginate-clay pellets containing mycelium of ARF18 were added to sandy soil in greenhouse tests to determine the formulation's efficacy in the suppression of Heterodera glycines. Pellet formulation variables included quantity of mycelium per pellet (0.0-3.9%), pellet size (2.3 or 8.3 mg), pellet application rate per unit soil (0.4 or 1.0% based on dry soil weight), and pellet storage (0 or 90 days). All of these variables affected efficacy. Nematode suppression was greatest (95%) with 8.3 mg pellets containing 3.9% mycelium that were not stored and applied at the rate of 1.0% of dry soil weight. Storage for 90 days reduced the efficacy of the pellets. The soybean cultivars tested were not equally good hosts of H. glycines, but reproduction of the nematode was reduced equally on all. The average suppression was 96% (range 86-99%). Similar suppression of reproduction occurred in tests with six races of H. glycines. ARF18 appeared to be nonspecific with regard to soybean cultivar and H. glycines race.

99mTc-HMPAO labeled leukocyte SPECT in intracranial lesions

BACKGROUND

Scintigraphy with 111In (indium-111)-oxine or 99mTechnetium-hexamethylpropyleneamine oxime (99mTc-HMPAO) labeled leukocytes has been used to differentiate brain abscess from brain tumor. However, there are false positive or false negative results from planar scintigraphic images. So a more specific and sensitive scintigraphic technique needs to be developed.

METHODS

Planar and single photon emission computed tomography (SPECT) images were obtained and reviewed in 14 patients with intracerebral ring-enhancing lesions on computed tomography (CT) or magnetic resonance imaging (MRI). In all patients, diagnosis was confirmed by histopathologic examination. The effect of steroids or antibiotics on scintigraphic finding was examined.

RESULTS

Abscess was confirmed in six patients, tumor in six, tuberculoma and cysticercosis in one each, respectively. In all the patients with abscess, SPECT showed increased focal activity irrespective of steroid or antibiotic therapy. Increased radioactivity, which could not be detected on planar images, could be identified in two patients with abscess. In three of the six patients with tumor, radiolabeled leukocytes did not accumulate in the tumor. In the other three patients with tumor, SPECT showed focally increased activity that was less intense than the activity shown in the patients with abscess.

CONCLUSIONS

99mTc-HMPAO labeled leukocyte SPECT is useful for the differential diagnosis of intracerebral ring-enhancing lesions, and the use of steroids or antibiotics does not influence the sensitivity of SPECT. Diagnostic sensitivity of scintigraphy with labeled leukocytes could be improved by SPECT in addition to planar image.

Portable cyst extractor: detecting cyst nematodes in the field

For on-site detection of cysts, a portable cyst extraction kit was constructed from nine readily available items. The portable cyst extractor detected cysts in a range of 1-117 cysts/100 g soil from 42 fields. Samples processed by this kit in fields were clean and easy to examine, possibly because the kit is a compact version of the standard wet-sieving technique used in the laboratory. The portable cyst extractor has several advantages over traditional survey methods: i) diagnosis of cyst infestations in the field accurately and rapidly most of the year and ii) reduction in the labor of samplings and transportation of soil samples.

Dimethylthiourea prevents MPTP-induced decrease in [3H]dopamine uptake in rat striatal slices

To determine whether oxygen free radicals are involved in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity, the effect of dimethylthiourea (DMTU), an effective hydroxyl radical scavenger, on MPTP-induced changes of [3H]dopamine uptake was investigated in rat striatal slices. The uptake of [3H]dopamine was decreased by MPTP treatment, and DMTU prevented the MPTP-induced decrease of [3H]dopamine uptake in a dose-dependent manner. The highest dose of DMTU used in this study completely prevented the MPTP-induced decrease of [3H]dopamine uptake. These results indicate that free radicals play a major role in the pathogenetic mechanism of MPTP-induced neurotoxicity.

Techniques for Isolation and Evaluation of Fungal Parasites of Heterodera glycines

A facultative fungal parasite, Arkansas Fungus 18 (ARF18), was isolated from at least 10 different sources of Heterodera glycines in different areas in the United States. Techniques used for isolation and in vitro evaluation of fungal parasites of H. glycines were described. Successful isolation of probable egg parasites depends on isolation from individual eggs. Selective isolation and a simple, yet definitive, screening system can increase the possibility of identifying effective biocontrol agents.

Persistent erythema infectiosum-like rash as a prodrome of acute lymphocytic leukemia

A 7-year-old boy had erythema infectiosum with typical manifestations. Over more than 40 days, these lesions showed no sign of regression, and chronic anemia became progressively more severe. Electron microscopic examination performed 20 days after onset showed abnormal Sezary-like lymphocytes. Bone marrow biopsy, which was performed to evaluate the anemia, was consistent with acute lymphocytic leukemia. Persistent parvovirus B19 infection may be connected with immunosuppression. Therefore, early electron microscopic study and bone marrow biopsy may be helpful for early diagnosis of hematologic malignancies.

Morphological study of surgically induced open neural tube defects in chick embryos--postoperative 24 hours

For the experimental study of neural tube defect (NTD), a surgical model has advantages over other models in a few aspects. It causes less functional derangement of cells and the NTDs can be made selectively by surgery. The authors planned to use the surgical model for the experimental study of NTD. As the first step for the studies, the chronological changes of morphology during the early postoperative period were investigated using postincubation 3-day chick embryos. The objectives of this study are (1) the morphological evaluation of the surgical model as a method for studies of open NTD, and (2) the observation of morphological changes for the first 24 hours after surgery which include 'overgrowth' appearance and the continuity between the surface ectoderm and the neuroectoderm. The morphological changes were observed by light microscope and scanning electron microscope. Immediately after surgery, typical open NTDs were observed. Morphologically they were very similar to the appearance of spontaneous (non-surgical) open NTDs. The opened neural tubes were everted progressively and they looked rather flat at 24 hours after surgery. Cellular hyperplasia ('overgrowth' appearance) was noted within 24 hours after surgery and became more prominent during the 24 hours. There was increasing continuity between the surface ectoderm and the neural tissue until 24 hours after surgery when the continuity looked almost complete. In conclusion, surgically induced NTDs are morphologically very similar to spontaneous NTDs.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral aspergillosis in immunologically competent patients

Aspergillosis of the central nervous system is a rare disease, especially if the patient's immune system is not compromised. The authors report three cases of cerebral aspergillosis in the immunocompetent state: a rhinocerebral form in a diabetic patient, a direct extension from chronic Aspergillus otitis media, and a postoperative Aspergillus brain abscess after brain tumor surgery. In spite of the poor prognosis of cerebral aspergillosis, two of the patients survived. The pathogenesis, predisposing factors, radiologic findings including magnetic resonance image, and the outcome are presented. The pertinent literature of cerebral aspergillosis is also reviewed.