Lambert-Eaton Myasthenic Syndrome Complicated by Anti-GABAB Receptor Encephalitis

A 74-year-old man experienced diplopia, generalized muscle weakness, and acute respiratory failure. He was diagnosed with Lambert-Eaton myasthenic syndrome (LEMS) and treated with immunotherapy, but no improvement was observed, and additional symptoms, including central apnea and hallucinations, appeared. Subsequent serum and cerebrospinal fluid (CSF) analyses confirmed the presence of GABAB receptor antibodies, indicating the coexistence of autoimmune encephalitis. Although there were no findings of malignancy, it is highly likely that occult small-cell lung carcinoma was present. When atypical symptoms occur in patients with LEMS, it is important to consider the possibility of concomitant autoimmune encephalitis.

Clinical Characteristics of Patients with Cryptococcal Meningitis in Hokkaido: A Case Series

We retrospectively reviewed the medical histories, examination results, treatments, and prognoses of nine patients with cryptococcal meningitis who were diagnosed and treated at Hokkaido University Hospital and its affiliated hospitals over the past 10 years. Cryptococcal meningitis can develop even in immunocompetent hosts, and its prognosis is poor owing to diagnostic difficulties and delayed treatment. Although liposomal amphotericin B and oral 5-fluorocytosine are standard therapies, voriconazole or intraventricular administration of amphotericin B may also be considered treatment options for refractory patients. Some patients develop delayed exacerbations owing to immunological mechanisms that require steroid therapy.

Prevalence of repeat expansions causing autosomal dominant spinocerebellar ataxias in Hokkaido, the northernmost island of Japan

In Japan, approximately 30% of spinocerebellar degeneration (SCD) is hereditary, and more than 90% of hereditary SCD is autosomal dominant SCD (AD-SCD). We have previously reported the types of AD-SCD in Hokkaido, twice. In this study, we investigated the status of AD-SCD mainly due to repeat expansions, covering the period since the last report. We performed genetic analysis for 312 patients with a clinical diagnosis of SCD, except for multiple system atrophy at medical institutions in Hokkaido between January 2007 and December 2020. The median age at the time of analysis was 58 (1-86) years. Pathogenic variants causing AD-SCD due to repeat expansion were found in 61.5% (192 cases). Spinocerebellar ataxia (SCA) 6 was the most common type in 25.3% (79 cases), followed by Machado-Joseph disease (MJD)/SCA3 in 13.8% (43), SCA1 in 6.4% (20), SCA2 in 5.1% (16), SCA31 in 4.8% (15), dentatorubral-pallidoluysian atrophy in 4.8% (15), SCA7 in 0.6% (2), and SCA8 in 0.6% (2). SCA17, 27B, 36, and 37 were not found. Compared to previous reports, this study found a higher prevalence of SCA6 and a lower prevalence of MJD/SCA3. An increasing number of cases identified by genetic testing, including cases with no apparent family history, accurately revealed the distribution of disease types in Hokkaido.

Case series: Downbeat nystagmus in SCA27B

BACKGROUND

Spinocerebellar ataxia (SCA) 27B, first reported in late 2022, is caused by the abnormal expansion of GAA repeats in the first intron of the FGF14 gene, which encodes the fibroblast growth factor 14.

CASE PRESENTATION

We present two late-onset cases, each manifesting mild cerebellar ataxia accompanied by omnidirectional downbeat nystagmus, which was enhanced in a suspended head position. None of the patients exhibited impaired head impulse or caloric tests. Repeat-primed PCR and targeted long-read nanopore sequence analysis of the FGF14 GAA repeat site identified more than 250 repeats, leading to the diagnosis of SCA27B.

DISCUSSION

Downbeat nystagmus is reported to be associated with disturbances in the suppression of the vestibulo-ocular reflex (VOR). Our patients with SCA27B demonstrated downbeat nystagmus, likely due to a disruption of the VOR at the level of the cerebellar cortex, a potentially characteristic clinical feature of SCA27B. We have included video footages of eye movements recorded using Frenzel goggles for these cases.

CONCLUSIONS

Omnidirectional downbeat nystagmus may be a distinctive clinical feature of SCA27B.

Experimental study on monitoring system of clinical beam purity in multiple-ion beam operation for heavy-ion radiotherapy

The National Institute of Radiological Sciences has investigated multiple-ion therapy using energetic beams of helium, carbon, oxygen, and neon ions, to improve treatment outcomes of refractory cancer. For this therapy, it is necessary to ensure the helium-ion beam purity to avoid irradiation by unwanted ions. Here, we develop a measurement method for monitoring beam purity. This method can measure the charge number of the ions in a high-purity beam using an ionization chamber and Faraday cup. In addition, it can be used to detect the contamination of the clinical helium-ion beam. We perform beam experiments to evaluate our beam-purity monitoring method and predict that our method is capable of detecting contamination below 1%.

Mucocutaneous inflammation in the Ikaros Family Zinc Finger 1-keratin 5-specific transgenic mice

BACKGROUND

Our genomewide association study documented an association between cold medicine-related Stevens-Johnson syndrome/toxic epidermal necrolysis (CM-SJS/TEN) and Ikaros Family Zinc Finger 1 (IKZF1). Few studies examined biological and pathological functions of IKZF1 in mucosal immunity. We hypothesized that IKZF1 contributes to the mucocutaneous inflammation.

METHODS

Human skin and conjunctival tissues were obtained for immunohistological studies. Primary human conjunctival epithelial cells (PHCjECs) and adult human epidermal keratinocytes (HEKa) also used for gene expression analysis. We also generated K5-Ikzf1-EGFP transgenic mice (Ikzf1 Tg) by introducing the Ik1 isoform into cells expressing keratin 5, which is expressed in epithelial tissues such as the epidermis and conjunctiva, and then examined them histologically and investigated gene expression of the epidermis. Moreover, Ikzf1 Tg were induced allergic contact dermatitis.

RESULTS

We found that human epidermis and conjunctival epithelium expressed IKZF1, and in PHCjECs and HEKa, the expression of IKZF1 mRNA was upregulated by stimulation with polyI:C, a TLR3 ligand. In Ikzf1 Tg, we observed dermatitis and mucosal inflammation including the ocular surface. In contact dermatitis model, inflammatory infiltrates in the skin of Ikzf1 Tg were significantly increased compared with wild type. Microarray analysis showed that Lcn2, Adh7, Epgn, Ifi202b, Cdo1, Gpr37, Duoxa1, Tnfrsf4, and Enpp5 genes were significantly upregulated in the epidermis of Ikzf1 Tg compared with wild type.

CONCLUSION

Our findings support the hypothesis that Ikaros might participate in mucocutaneous inflammation.

Inhibition of Bach1 ameliorates indomethacin-induced intestinal injury in mice

BTB and CNC homolog 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1). It plays an important role in the feedback regulation of HO-1 expression, which protects cells from various insults including oxidative stress and inflammatory cytokines. However, the role of Bach1 in intestinal inflammation remains unclear. In this study, the role of Bach1 in intestinal mucosal injury was elucidated using 8-week-old female C57BL/6 (wild-type) and homozygous Bach1-deficient C57BL/6 mice. Intestinal mucosal injuries induced by a single subcutaneous administration of indomethacin were evaluated macroscopically, histologically, and biochemically. Mucosal protein content and chemokine mRNA levels were determined by real-time PCR. Our results showed that the indomethacin-induced intestinal injury was remarkably improved in Bach1-deficient mice. Histological examination showed that the area of injured lesion was decreased in Bach1-deficient mice compared to wild-type mice. Administration of indomethacin induced expression of inflammatory chemokines such as KC, MIP1alpha and MCP1, which was suppressed in Bach1-deficient mice. Myeloperoxidase activity in the intestinal mucosa was also significantly decreased in Bach1-deficient mice. Additionally, Bach1 deficiency enhanced immunopositivity of HO-1 in the intestinal mucosa after indomethacin administration. Disruption of the Bach1 gene thus caused inhibition of mucosal injury, indicating that inhibition of Bach1 may be a novel therapeutic strategy for treating indomethacin-induced intestinal injury.

Dextran sulfate sodium-induced acute colonic inflammation in angiotensin II type 1a receptor deficient mice

OBJECTIVE

Angiotensin II (Ang II) receptor blockers have been reported to contribute to cytoprotective effects in various organs. However, the role of renin-angiotensin system (RAS) in modulation of the inflammatory bowel disease (IBD) remains unclear. In this study we assessed the role of angiotensin II type 1a (AT1a) receptor on the outcome of dextran sulfate sodium (DSS)-induced acute colitis by employing AT1a receptor deficient mice.

MATERIALS AND METHODS

The acute colitis was induced in wild type (WT) and AT1a receptor deficient mice by giving orally 3% DSS in drinking water for 7 days.

RESULTS

Induction of DSS colitis resulted in up-regulation of Ang II and AT1a receptor in the colonic mucosa of WT mice. In parallel, loss of body weight, an increase in disease activity index (DAI), and the shortening of colon were found in DSS-challenged WT mice. In addition, an increase in thiobarbituric acid (TBA)-reactive substances and myeloperoxidase (MPO) activity, along with the up-regulation of tumor necrosis factor (TNF)-alpha were detected in the colonic mucosa of DSS-challenged WT mice. The endpoints mentioned above were significantly ameliorated in DSS-challenged AT1a receptor deficient mice.

CONCLUSIONS

RAS is involved in the pathophysiology of DSS-induced colitis and AT1a receptor may be a novel therapeutic target for the treatment of IBD.

Size effects of nanomaterials on lung inflammation and coagulatory disturbance

Effects of nano-sized materials (nanomaterials) on subjects with predisposing inflammatory disorders have not been well elucidated. This study examined the effects of pulmonary exposure to TiO2 nanomaterials on lung inflammation induced by lipopolysaccharide (LPS) and consequent systemic inflammation with coagulatory disturbance in mice, in particular regarding their size-dependency. Also, gene expression pattern in the lung was compared among the experimental groups using cDNA microarray analysis. ICR male mice were divided into 8 experimental groups that intratracheally received vehicle, three sizes (15, 50, 100 nm) of TiO2 nanomaterials (8 mg/kg), LPS (2.5 mg/kg), or LPS plus nanomaterials. Twenty four h after the treatment, these nanomaterials exacerbated the lung inflammation and vascular permeability elicited by LPS, with an overall trend of amplified lung expressions of cytokines such as interleukin (IL)-1beta, macrophage chemoattractant protein (MCP)-1, and keratinocyte chemoattractant (KC). LPS plus nanomaterials, especially of a size less than 50 nm, elevated circulatory levels of fibrinogen, IL-1beta, MCP-1, and KC, and von Willebrand factor as compared with LPS alone. The enhancement tended overall to be greater with the smaller nanomaterials than with the larger ones. cDNA microarray analyses revealed that there was no difference in gene expression pattern between the LPS group and the LPS + nanomaterial. These results suggest that nanomaterials exacerbate lung inflammation related to LPS with systemic inflammation and coagulatory disturbance, and that the exacerbation is more prominent with smaller nanomaterials than with larger ones.

Luminescent FeSi(2) crystal structures induced by heteroepitaxial stress on Si(111)

The crystal structures and the luminescent properties of FeSi(2) in the FeSi(2)/Si heteroepitaxial system have been investigated by first principles calculations. The results indicate that the heteroepitaxial beta-FeSi(2) facing Si(111) by the (110) plane will be deformed from an orthorhombic to a monoclinic P2(1)/c structure with a gamma angle of 95 degrees. The strained crystal has a direct gap band structure and a finite oscillator strength of 0.7 between the band edges at the Y point. Since an indirect type band structure is obtained for other heteroepitaxial relationships, as well as for the bulk beta-FeSi(2), we propose the strained FeSi(2)(110)/Si(111) structure to be the origin of the luminescence observed in the FeSi(2)/Si systems.

A novel G-protein-coupled receptor gene expressed in striatum

Differential display screening for region-specific transcripts in rat brain revealed a novel striatum-specific transcript encoding an orphan G-protein-coupled receptor (GPCR) designated Strg/Gpr88 for striatum-specific GPCR. We isolated its homologues from human (HGMW-approved symbol GPR88) and mouse and mapped them to chromosomes 1p21.3 and 3G1, respectively. These loci are syntenic to each other, thereby suggesting their orthology. The predicted primary sequences of Strg/Gpr88 proteins are highly conserved between human and rodents and show the highest level of homology to receptors for biogenic amines. However, Strg/Gpr88 lacks some residues conserved in all known biogenic amine receptors and hence may represent a novel subtype of GPCR. Northern blot and in situ hybridization analyses revealed that Strg/Gpr88 transcripts are expressed almost exclusively in striatum in both human and rodents. Remarkable conservation in primary structure and a unique expression pattern may indicate a role for Strg/Gpr88 in the fundamental functions of striatum such as the control of motor behavior.

Analysis of spinocerebellar ataxia type 2 gene and haplotype analysis: (CCG)1-2 polymorphism and contribution to founder effect

Spinocerebellar ataxia type 2 is a familial spinocerebellar ataxia with autosomal dominant inheritance. The gene responsible was recently cloned and this disorder was found to be the result of a CAG expansion in its open reading frame. We analysed 13 SCA2 patients in seven unrelated families in Gunma Prefecture, Japan. In four of the seven families, we detected CCG or CCGCCG interruptions in only the expanded alleles. Cosegregation of these polymorphisms with SCA2 patients was established within each family. Together with the results of haplotype analyses, we considered that at least two founders were present in our area and that these (CCG)1-2 polymorphisms may make analysis of founder effects easier. By sequencing analysis we found that although the number of the long CAG repeat varied in each subclone of expanded alleles, these polymorphisms did not change their configuration. This finding suggests that CCG or CCGCCG sequences are stable when surrounded by the long CAG repeat and a single CAG. Moreover, the presence of these polymorphisms may lead to miscounting the repeat size by conventional estimation using a size marker such as an M13 sequencing ladder. Therefore we should consider these polymorphisms and accurately determine the repeat size by sequencing.

Molecular analysis of a de novo mutation for spinocerebellar ataxia type 6 and (CAG)n repeat units in normal elder controls

Spinocerebellar ataxia type 6 (SCA6) is an autosomal dominant spinocerebellar degenerative disease caused by CAG repeat expansions in the human alpha1A voltage-dependent calcium channel subunit gene (CACNL1A4). We analyzed 15 SCA6 patients in 14 unrelated Japanese families and 52 healthy Japanese aged over 74 years. Sequence analysis was performed to determine the correct number of CAG repeats. The expanded CAG repeat number was 23.6+/-2.1 (mean+/-S.D., n=15) with a range of 20-29, and the shortest expanded allele was 20 repeats. Moreover, the analysis of normal subjects revealed that the CAG repeat number of normal alleles was 12.3+/-1.9 (n=104) with a range of 7-18. We concluded that the normal range of CAG repeats in the CACNL1A4 gene is 18 or less, and that the disease range is 20 or more. Of 15 SCA6 patients, three sporadic cases were observed. In one male patient with 26 CAG repeats, the CAG repeat numbers of his parents were within normal range. His expanded allele was considered to be caused by an expansion of a normal allele from his mother (14 or 17 repeats). This is the first SCA6 case which was genetically proven to occur due to a de novo mechanism, suggesting that larger CAG repeats of normal alleles in the CACNL1A4 gene may be unstable and result in full expansion.

Familial spinocerebellar ataxia with cerebellar atrophy, peripheral neuropathy, and elevated level of serum creatine kinase, gamma-globulin, and alpha-fetoprotein

Here, we report a familial spinocerebellar ataxia (FSCA), which has clinical features similar to Friedreich's ataxia, an ataxia with isolated vitamin E deficiency, and ataxia telangiectasia. However, the serum levels of creatine kinase, gamma-globulin, and alpha-fetoprotein were elevated, and biochemical and genetic analyses ruled out diagnosis of these three ataxias as well as other FSCAs. Thus, this family is thought to have a new type of FSCA.

Longitudinal study of cerebrospinal fluid levels of tau, A beta1-40, and A beta1-42(43) in Alzheimer's disease: a study in Japan

To clarify the alterations of tau, amyloid beta protein (A beta) 1-40 and A beta1-42(43) in the cerebrospinal fluid (CSF) that accompany normal aging and the progression of Alzheimer's disease (AD), CSF samples of 93 AD patients, 32 longitudinal subjects among these 93 AD patients, 33 patients with non-AD dementia, 56 with other neurological diseases, and 54 normal control subjects from three independent institutes were analyzed by sensitive enzyme-linked immunosorbent assays. Although the tau levels increased with aging, a significant elevation of tau and a correlation between the tau levels and the clinical progression were observed in the AD patients. A significant decrease of the A beta1-42(43) levels and a significant increase of the ratio of A beta1-40 to A beta1-42(43) were observed in the AD patients. The longitudinal AD study showed continuous low A beta1-42(43) levels and an increase of the ratio of A beta1-40 to A beta1-42(43) before the onset of AD. These findings suggest that CSF tau may increase with the clinical progression of dementia and that the alteration of the CSF level of A beta1-42(43) and the ratio of A beta1-40 to A beta1-42(43) may start at early stages in AD. The assays of CSF tau, A beta1-40, and A beta1-42(43) provided efficient diagnostic sensitivity (71%) and specificity (83%) by using the production of tau levels and the ratio of A beta1-40 to A beta1-42(43), and an improvement in sensitivity (to 91%) was obtained in the longitudinal evaluation.

Combination assay of CSF tau, A beta 1-40 and A beta 1-42(43) as a biochemical marker of Alzheimer's disease

Cerebrospinal fluid samples from a total of 157 subjects consisting of 55 patients with sporadic Alzheimer's disease (AD), 34 normal controls, 23 patients with non-AD dementia, and 45 with other neurological diseases were examined by ELISA of tau, A beta 1-40, and A beta 1-42(43). The AD group had a significantly higher level of tau than the normal control group (P < 0.001), and the diagnostic sensitivity was 31% and specificity was 94%. CSF A beta 1-40 levels did not show any significant differences. Although the level of A beta 1-42(43) was decreased significantly in the AD group compared to the control group (P < 0.005), the overlap of A beta 1-42(43) levels among all groups meant that none of the AD samples exceeded the cut-off value, the mean 2SD of normal control subjects. Reduction of A beta 1-42(43) levels in AD resulted in a significant increase in the ratio of A beta 1-40 to A beta 1-42(43) (A beta ratio) as an improved marker. The diagnostic sensitivity and specificity of A beta ratio were 51% and 82% respectively. The three indexes, using the tau level and A beta ratio (tau or A beta ratio, deviation score and tau x A beta ratio), showed better sensitivity (58%, 67%, 69%) and specificity (82%, 86%, 88%) than previously reported methods. Combination assay for CSF tau, A beta 1-40 and A beta 1-42(43) in CSF is a biological marker of AD and may be useful to biochemically monitor subjects under treatment.

Analysis of spinocerebellar ataxia type 2 in Gunma Prefecture in Japan: CAG trinucleotide expansion and clinical characteristics

We analyzed 13 patients with spinocerebellar ataxia type 2 (SCA2) in seven unrelated families who live in Gunma Prefecture, Japan (population approx. 2,000,000), and documented the clinical and molecular properties correlated with the CAG repeat expansion. Twelve of the 13 patients and one presymptomatic female were genetically examined, and the CAG repeat number of the expanded and normal alleles was 40.8+/-4.8 (mean+/-S.D., n=13) and 22+/-0 (n=13), respectively. The repeat size of the expanded alleles was inversely correlated with the patients' age at onset. Paternal anticipation was observed, accompanied by an increase of the CAG repeat size. The patients presented here were clinically characterized by a relatively higher frequency of slow saccades, hyporeflexia, hypotonia, and tremor. A number of peaks in the expanded allele on polyacrylamide gel electrophoresis showed the presence of cell mosaicism in SCA2 as well. In Gunma Prefecture, SCA2, Machado-Joseph disease and spinocerebellar ataxia type 6 are almost equally present and at higher frequencies than spinocerebellar ataxia type 1 and hereditary dentatorubropallidoluysian atrophy, which are rare. Thus, the difference of frequency of autosomal dominant spinocerebellar ataxias may be present in Japan.

Analysis of the McLeod syndrome gene in three patients with neuroacanthocytosis

McLeod syndrome is a rare X-linked disorder involving neurological defects and acanthocytosis. We examined the XK gene in three patients with neuroacanthocytosis, one of whom had cardiomyopathy, and his symptoms were very similar to those of McLeod syndrome. We found two new transversions (C to G at codon 204 and G to C at codon 205) in exon 3 in all those cases. However, the transversion at codon 205 was found in all 70 Japanese normal subjects and four non-Japanese (two Caucasian males, one Chinese female and one Micronesian female) and that at codon 204 was also detected in all 14 normal Japanese males and the four non-Japanese. These findings suggest that they are not the cause of McLeod syndrome, but normal polymorphisms which have not been reported. Moreover, there is a possibility that patients with neuroacanthocytosis similar to McLeod syndrome exist without the XK gene abnormalities.

Mitotic and meiotic stability of the CAG repeat in the X-linked spinal and bulbar muscular atrophy gene

X-linked spinal and bulbar muscular atrophy (SBMA) occurs due to an expansion of the trinucleotide repeat (CAG)n in the androgen receptor gene. Anticipation is relatively rare in SBMA in contrast to spinocerebellar ataxia type 1 (SCAl), and dentatorubral and pallidoluysian atrophy (DRPLA) which show obvious paternal anticipation. The differences in the CAG repeat number were compared among sperm, leukocytes and skeletal muscles of SBMA patients. In SBMA, the sperm of most patients and the skeletal muscle of all patients showed the same repeat number as their leukocytes, whereas the increase in the repeat number from leukocytes to sperm was evident in SCA1 and DRPLA patients. The higher mosaicism level in sperm compared with leukocytes was common in SBMA, SCA1 and DRPLA, and the level of sperm was lower in SBMA than in SCA1 and DRPLA. Thus, spermatogenesis was suggested to be strongly associated with paternal anticipation. The mosaicism level was smaller in SBMA than in other (CAG)n expanded disorders, and smallest in the SBMA carrier females. These findings demonstrate that the CAG repeat in SBMA is relatively stable in mitotic and meiotic, processes, and there is a possibility that the lower mosaicism level of the carrier females compared with the SBMA patients is associated with X-linked recessive inheritance.

[A case of pulmonary tumorlet with tuberculoma misdiagnosed as small cell lung carcinoma by transbronchial lung biopsy]

A 59-year-old woman was picked up by chest X-ray findings. Her CT scan film showed a tumor shadow in the upper lobe of the left lung, and by transbronchial lung biopsy, she was diagnosed as a small cell lung carcinoma. Lobectomy was performed, but the lesion was diagnosed as tuberculoma by frozen section. Furthermore, on postoperative histological examination, a minute lesion of tumorlet, which was histologically identical to that preoperatively detected by transbronchial lung biopsy was found in the adjacent tissues of the tuberculoma. Pulmonary tumorlet is clinically a rare lesion, but the diagnosis and treatment for small-sized tumor or tumor-like lesion may be carefully done, taking into account the existence or co-existence of tumorlet lesion.

[Experimental and clinical studies on ischemic lesions of the large intestine]

To clarify the pathogenesis and endoscopic features of ischemic lesions of the colon, experimental ischemia was induced in dogs by arterial ligation, gelfoam injection, and clipping. In addition, clinical and endoscopic features of ischemic lesions in ischemic colitis cases in human were studied. In the experimental model, arterial ligation including marginal arteries frequently induced erosions in the large intestine, whereas ligation of the colic artery alone did not induce apparent mucosal lesions of the large intestine. Gelfoam injection to produce thrombi into caudal mesenteric artery or middle colic artery induced ulcers with a high rate of incidence and frequently accompanied by intestinal perforation. Temporal impairment of blood supply by arterial clipping produced erosion, but not ulcers. A high incidence of erosion was obtained in a group that underwent clipping for a prolonged period and a group of receiving Alosenn. Mucosal blood flow measured by the hydrogen gas clearance method was significantly decreased at 1 hr and 4 hr after gelfoam injection compared with those after arterial ligation. In human cases of ischemia following arterial surgery, endoscopic features were similar to those lesions of the experimental ischemia induced by gelfoam injection. These results suggest that thrombi in peripheral small arteries may play a major role in the pathogenesis of ischemic lesions of the large intestine.

Resistance of the melibiose carrier to inhibition by the phosphotransferase system due to substitutions of amino acid residues in the carrier of Salmonella typhimurium

The melibiose carrier of Salmonella typhimurium is under the control of the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS). We isolated mutants of the melibiose carrier that showed resistance to inhibition via the PTS. Growth of the mutants on melibiose was not inhibited by 2-deoxyglucose, a non-metabolizable substrate of the PTS, although growth of the parent strain was inhibited. Transport activity of the melibiose carrier in the mutants was fairly resistant to inhibition by 2-deoxyglucose, although the activity in the parent was sensitive to inhibition. We cloned the mutated melB gene that encodes the melibiose carrier, determined the nucleotide sequences, and identified replaced nucleotides. The mutations resulted in substitutions of Asp-438 with Tyr, Arg-441 with Ser, or Ile-445 with Asn. All of these residues are in the COOH-terminal region of the carrier. The secondary structure of this region is predicted to be an alpha-helix, and the mutated residues were on the same side of the helix. This region showed sequence similarity to a region of the MalK protein, in which substitution of amino acid residues also resulted in PTS-resistant mutants. Thus the COOH-terminal portion of the melibiose carrier is important for the interaction of dephosphorylated IIIGlc, which is an entity causing reversible inactivation of the carrier.

Cloning and sequencing of the melB gene encoding the melibiose permease of Salmonella typhimurium LT2

The nucleotide sequence of the melB gene coding for the Na+ (Li+)/melibiose symporter of Salmonella typhimurium LT2 was determined, and its amino acid sequence was deduced. It consists of 1428 bp, corresponding to a protein of 476 amino acid residues (calculated molecular weight 52,800). The amino acid sequence is homologous to that of the melibiose permease of Escherichia coli K12, with 85% identical residues. All, except one, of the amino acid residues that have been reported to be important for cation or substrate recognition in the melibiose permease of E. coli are conserved in the melibiose permease of S. typhimurium. In addition, part of the sequence resembles the lactose permease of Streptococcus thermophilus, the animal glucose transporter (GLUT1), the plasmid-coded raffinose permease (RafB), and the NADH-ubiquinone oxidoreductase chain 4 (Nuo4) of Aspergillus amstelodami.

[Color Doppler evaluation of a specific left ventricular flow pattern in a case of left ventricular pseudoaneurysm]

This report describes a case of left ventricular pseudoaneurysm examined by phonocardiography, two-dimensional echocardiography, Doppler color flow mapping, continuous wave and conventional pulsed Doppler echocardiography. The patient had early systolic and early diastolic murmurs. The pseudoaneurysm sac and the site of left ventricular rupture were identified by two-dimensional echocardiography. The flow between the left ventricle and the pseudoaneurysm were imaged by Doppler color flow mapping. Two jets from the left ventricle were directed toward the aneurysm during systole, and from the aneurysm toward the left ventricle in early diastole. Continuous wave Doppler and high pulse repetition frequency Doppler echocardiography demonstrated the maximum flow velocity in systole to be 3 m/sec and in early diastole, 1.7 m/sec. Those flow patterns between the left ventricle and the pseudoaneurysm could have been closely related to the murmur. Doppler echocardiography thus proved useful for detecting specific flow patterns related to a left ventricular pseudoaneurysm.

Detection of DR antigen on leukemic cells from a patient suffering from adult T-cell leukemia and progressive systemic sclerosis

This report concerns an unusual case of adult T cell leukemia (ATL) complicated with progressive systemic sclerosis (PSS). The surface markers of peripheral blood mononuclear cells (PBM) and lymph node cells, both of which mainly consisted of leukemic cells, were examined. The effect of these cells on the pokeweed mitogen (PWM)-induced IgG synthesis by normal PBM also was studied. The leukemic cells formed rosettes with sheep red blood cells (SRBC; E) and expressed T cell antigen, Leu-1, and DR antigen. The detection of cell surface antigens was carried out by employing monoclonal antibodies against these antigens. We diagnosed this case as DR positive ATL. In terms of the immunoregulatory function of these leukemic cells, the co-culture experiments showed that these cells had some suppressive effect on the PWM-induced IgG production by allogeneic normal PBM.