GH secretory dynamics and responsiveness to SMS 201-995 treatment in acromegaly

Recently, SMS 201-995, a long acting somatostatin analogue, has been used in successful therapy for inhibition of growth hormone (GH) levels in acromegaly. But, it was reported that inhibitory and clinical effects in the individual patient were different in many cases. Therefore, to find the predictive factor for patients with effective inhibition of GH, we investigated the paradoxical response to thyrotropin releasing hormone (TRH), growth hormone releasing hormone (GHRH) and diurnal variation of GH secretion between responders and non-responders to SMS 201-995. The results were as follows; Responders, patients with suppressive response to SMS 201-995, totalled 4 of 8 patients. The paradoxical response of GH to TRH was observed in 3 of 4 responders and 3 of 4 non-responders. The response of GH to GHRH was not noted in either of the groups. The diurnal variation of GH secretion showed in one of the responders and in 3 of the non-responders. These results suggested that the absence of diurnal variation of GH secretion was a characteristic feature of responders to SMS 201-995 and thus diurnal variation of GH secretion could be used as a predictive factor for SMS 201-995 therapy, and the pathogenetic mechanism of acromegaly might be dependent on the controlled regulation of GHRH and endogenous somatostatin.

The clinical utility of microalbuminuria in nephrotic syndrome with complete remission, isolated microscopic hematuria and renal transplantation donors

Using urinary microalbumin radioimmunoassay, we evaluated the clinical utility of microalbumin excretion in nephrotic syndrome with complete remission, isolated microscopic hematuria and kidney donors in reanl transplantation. The highest value in normal controls was 10.86 μg/min, and the upper normal level was set to 15 μg/min. The range of microalbuminuria in patients with nephrotic syndrome with complete remission was 1.67 μg/min to 32.5 μg/min. There was no significant correlation between the recurrence rate and microlbuminuria level in nephrotic syndrome with complete remission. The range of microalbuminuria levels in isolated microscopic hematuric patients was between 2.37μg/min and 103.2 μg/min. There was no singificant correlation between the amount of the red blood cells in urine and the level of microalbuminuria in the isolated microscopic hematuric patients. Most renal transplantation donors showed a normal range of microalbuminuria after nephrectomy. The aim of this study was to evaluate the clinical utility of urinary microalbuminuria in diseases other than diabetes. We concluded that further extensive and specific study will be required to determine the clinical utility of microalbuminuria.

Identification of cDNA encoding an additional alpha subunit of a human GTP-binding protein: expression of three alpha i subtypes in human tissues and cell lines

The guanine nucleotide-binding proteins (G proteins), which mediate hormonal regulation of many membrane functions, are composed of alpha, beta, and gamma subunits. We have cloned and characterized cDNA from a human T-cell library encoding a form of alpha i that is different from the human alpha i subtypes previously reported [Didsbury, J. R., Ho, Y.-S. & Snyderman, R. (1987) FEBS Lett. 211, 160-164 and Bray, P., Carter, A., Guo, V., Puckett, C., Kamholz, J., Spiegel, A. & Nirenberg, M. (1987) Proc. Natl. Acad. Sci. USA 84, 5115-5119]. alpha i is the alpha subunit of a class of G proteins that inhibits adenylate cyclase and regulates other enzymes and ion channels. This cDNA encodes a polypeptide of 354 amino acids and is assigned to encode the alpha i-3 subtype of G proteins on the basis of its similarity to other alpha i-like cDNAs and the presence of a predicted site for ADP ribosylation by pertussis toxin. We have determined the expression of mRNA for this and two other subtypes of human alpha i (alpha i-1 and alpha i-2) in a variety of human fetal tissues and in human cell lines. All three alpha i subtypes were present in the tissues tested. However, analysis of individual cell types reveals specificity of alpha i-1 expression. mRNA for alpha i-1 is absent in T cells, B cells, and monocytes but is present in other cell lines. The finding of differential expression of alpha i-1 genes may permit characterization of distinct physiological roles for this alpha i subunit. mRNA for alpha i-2 and alpha i-3 was found in all the primary and transformed cell lines tested. Thus, some cells contain all three alpha i subtypes. This observation raises the question of how cells prevent cross talk among receptors that are coupled to effectors through such similar alpha proteins.

Identification and surface phenotypic characterization of phosphorylcholine-specific idiotype-bearing T cells

We have employed two-color staining with monoclonal anti-T-cell markers and a broadly reactive, nonbinding site monoclonal anti-idiotype to permit direct visualization of idiotype-bearing T cells in mouse lymph nodes following immunization with phosphorylcholine. Double positive cells peak in incidence on Days 8 to 12, as 17% of total idiotype+ cells but as only 0.7% of T cells. Such cells are antigen-specific, appearing in peripheral lymph nodes only following phosphorylcholine challenge. While Lyt-2+ and L3T4+ subsets are represented and both subsets reexpress the idiotypic determinant following its enzymatic removal, the L3T4+ subset represents the majority of idiotype+Thy-1+ cells. These findings raise the possibility that antigen-specific receptors on T and B cells, encoded by entirely different genetic information, may exhibit similarities in tertiary structure in portions of the molecules not directly involved in antigen binding. This is the first determination of the phenotype and chronology of appearance of idiotype-bearing normal T cells following immunization. It is consistent with previous reports of functionally defined idiotype-bearing T cells and provides direct support for the existence of such cells.

An AT rich region of dyad symmetry is a promoter element in the yeast TRP1 gene

Transcription from the yeast TRP1 promoter results in two classes of transcript, I and II, that are influenced by different promoter elements. The 5' flanking region contains a region of dyad symmetry (RDS) which contains a 12 nucleotide AT rich inverted repeat, separated by a 21 bp spacer region. The RDS lies within a region of the promoter required for transcription of class II RNAs. A series of internal deletions and insertions have been constructed in vitro around the RDS and the effect of each mutation on transcription has been analysed. Deleting either of the repeats abolishes class II transcription and disruption of both repeats influenced the levels of the larger class I transcripts. Deletion of the spacer had no effect but increasing the length to 33 bp reduced transcription. These results show that the RDS is an important component of the TRP1 promoter, that both repeats must be preserved and that there is some constraint on the spacing of the repeats for maximal function.

Endobronchial metastasis of malignant melanoma, diagnosed by bronchoscopy--report of a case

Endobronchial metastasis occurs in about 2% to 5% of patients dying of solid tumors of extrathoracic origin. These metastatic tumors can simulate bronchogenic carcinoma and presenting symptoms include cough, hemoptysis, dyspnea and wheezing. In most cases of endobronchial metastasis, the histologic finding of the bronchoscope biopsy suggests the correct diagnosis. There are only a few reports of endobronchial metastasis from malignant melanoma. We report a case of malignant melanoma with endobronchial metastasis presenting with hemoptysis simulating primary bronchogenic carcinoma.

Transformation of Neurospora crassa with the trp-1 gene and the effect of host strain upon the fate of the transforming DNA

Neurospora trp-1+ transformants, obtained by transforming a trp-1 inl strain with plasmid DNA containing the wild type trp1+ gene, were characterized by genetic and Southern blot analyses. The transforming trp-1 gene integrated at or near the resident site in all of the trp-1+ transformants obtained with circular DNA or DNA cut within the trp-1 coding region. The frequency of homologous integration decreased substantially when the donor DNA was cleaved outside the trp-1 coding region. The transformants were very stable mitotically and, in general, also showed meiotic stability. Analysis of trp-1+ transformants obtained with another recipient strain, trp-1+ ga-2 aro-9 inl, showed that homologous integration of donor DNA occurred in only 20% of the transformants, whether circular or linear DNA was used. Thus, the host strain employed for transformation appears to be a major factor in determining the fate of transforming DNA. Southern blot analysis of transformants showed that integration of the transforming DNA at the homologous site occurred by double crossover or gene conversion events rather than by insertion of the entire plasmid DNA. Multiple and apparently non functional integration events were observed in some transformants.

Multiple cis-active elements in the long control region of bovine papillomavirus type 1 (BPV-1)

A 1.0 kb region of the BPV-1 genome (the long control region, LCR), contains controls for transcription and the origin of replication. Transcription directed by the LCR is activated by the viral encoded E2 protein. To define the essential cis acting elements that are required to control transcription we have constructed a series of deletions throughout the LCR. We have identified three important domains in the LCR, two of which respond to E2. We have analysed the ability of small subcloned regions of the E2 responsive domains to act as enhancers in a heterologous assay system. This has led to the identification of five independent E2 responsive elements. We have shown that a fragment of only 38 base pairs is sufficient to respond to activation by E2. We also present evidence to suggest two types of E2 responsiveness that result in strong or weak activation. Strong response is correlated with the presence of the sequence 5'-ACCG/TNNNC/TCGGTGC-3' whereas weak response is correlated with the presence of a related sequence 5'-ACC(N)6GGT-3'. The contribution of these multiple elements to viral transcription is discussed.

MR imaging of a renal oncocytoma

A renal mass showing no invasion of the pararenal fascia, a distinct margin between tumor and remaining kidney, vascular patency, and large ring-like calcification detected on magnetic resonance imaging may suggest the diagnosis of renal oncocytoma.

Gamma interferon modulates epidermal cell proliferation and mixed epidermal cell-lymphocyte reaction

Gamma interferon (gamma-IFN), a lymphokine produced by activated T lymphocytes, has a variety of effects on target cell. It induces class II antigens of the major histocompatibility complex not only in immunocompetent cells but also in non-immunocompetent cells. gamma-IFN also can exert, in addition to anti-viral activity, a series of anticellular effects on a variety of cell types. The effects of gamma-IFN on the proliferation of cultured epidermal cell (EC) and induction of HLA-DR antigen expression by EC (HLA-DR+KC) were studied. Furthermore, the immunologic role of HLA-DR+KC in the mixed epidermal cell-lymphocyte reaction (MECLR) was studied. The antiproliferative effect of gamma-IFN on the cultured EC was seen 3 days after treatment of gamma-IFN and the effect was dose-dependent. Number of HLA-DR+KC was increased dose-dependently with treatment of gamma-IFN. In MECLR, HLA-DR+KC had been found to exert stimulatory role on allogenic lymphocytes. However, there was no significant role of HLA-DR+KC on autologous lymphocytes.

Ia antigen mediated specific antigen presenting function of articular chondrocytes

The ability of articular chondrocytes to function as antigen presenting cells (APC) was examined. Rabbits were immunized with ovalbumin (OVA) in complete Freund’s adjuvant. Four weeks later, axillary lymph nodes were obtained. Spleen cells were used as positive controls. Chondrocytes were separated by collagenase, DNAse, and hyaluronidase digestion of dissected cartillage from femurs and tibias. Nylon wool purified T lymphocytes were cocultured with OVA pulsed and mitomycin-C treated chondrocytes and spleen cells. The proliferative response of autologus T lymphocytes was measured by ³H-thymidine uptake. Chondrocytes as well as spleen cells showed antigen presenting acitivty. This activity was inhibited by mouse monolonal anti-rabbit la antibody. These results indicate that articular chondrocytes function as antigen presenting cells in common with spleen cells, la antigen is a regulatory element in conjunction with soluble antigen for this process.

HLA and insulin-dependent diabetes mellitus in Koreans

Specific allelic associations vary among ethnic groups. We studied the distribution of HLA-A, -B, -C and -DR antigens in 41 patients with insulin-dependent diabetes mellitus (IDDM) and 280 unaffected persons in Korea. HLA typing was performed by the standard microlymphocytotoxicity test using antisera supplied by the Third Asia-Oceania Histocompatibility Workshop Conference (3rd AOHWC, 1986). There was no association between HLA-A, -B, or -C and IDDM. However, the frequencies of HLA-DR3 and HLA-DR4 were increased in the patients as compared with the controls (19.5% vs 4.3%, RR 5.4, corrected p < 0.005 for DR3 and 61.0% vs 36.4%, RR 2.7, corrected p < 0.05 for DR4). Also a decreased frequency of HLA-DR2 was found in the patients with IDDM (9.8% vs 32.1%, RR 0.3, corrected p < 0.05). These results emphasize the differences in HLA-IDDM associations among different ethnic groups.

Ultrasound changes of the gallbladder wall in cholecystitis: a sonographic-pathological correlation

To assess the pathological basis of the changes seen on ultrasound examination of the gallbladder wall in cholecystitis, the appearances of the gallbladder wall were analysed in 17 patients with acute cholecystitis and 27 patients with chronic cholecystitis, and correlated with the pathological specimens removed at surgery. A thin echo reduced layer within the echogenic gallbladder wall corresponds to a complex of subserosal oedema, haemorrhage and inflammatory cell infiltration, or to muscular hypertrophy. Indistinctness or a low echogenicity rind along the inner margin represents mucosal sloughing or obliteration of the mucosal folds. Uniformly decreased echogenicity of the wall is caused by severe inflammatory change with sloughing of the mucosa or obliteration of the mucosal folds. These ultrasound signs are considered to be valuable signs of cholecystitis.

Nondestructive depth profiling of ZnS and MgO films by spectroscopic ellipsometry

Spectroscopic ellipsometric (SE) measurements followed by linear-regression analysis of the SE data obtained on ZnS and MgO films on vitreous silica substrates reveal the distribution of voids (or low-density regions) in these transparent thin films.

Effects of interferons on human B-cell differentiation in vitro

The effects of interferons (IFN) on in vitro differentiation of B-lymphocytes were studied. Peripheral lymphocytes from normal subjects were cultivated under polyclonal activator pokeweed mitogen (PWN) or Epstein-Barr virus (EBV) stimulation. The secreted Ig in the culture supernatants were measured for IgM by ELISA method.

To determine the cellular level of IFN action T-cell enriched fraction (Te) or B-cell enriched fraction (Be) were preincubated with IFN prior to recombination culture.

IFN had modulatory activities on Ig production; at low to moderately high doses (10–1000 U/ml of IFN-alpha or 12–120 U/ml of IFN-gamma) stimulating when IFN was added until 48 hr after the start of the culture, while after 72 hr from culture start IFN suppressed Ig production.

Preincubation of Be-cells with moderately high doses of IFN (120 U/ml of IFN-gamma or 1000 U/ml of IFN-alpha) prior to PWM-stimulation suppressed Ig production. Likewise, in EBV-stimulated culture, high dose IFN suppressed Ig production. But low dose of IFN enhanced ig production in EBV-stimulated culture.

Preincubation of Te-cells with IFN prior to PWM-stimulation with Be-cells enhanced the Ig production. The T-cell subset analysis at the end of these culture showed enhanced ratio of T-helper cell relative to T-suppressor cells, suggesting increased T-helper cell proliferation after incubation with IFN.

Thus, it is concluded that IFNs have modulatory activities on B-cell differentiation. The mechanism seems to be direct effects on B-cells (in PWM and EBV system) as well as through T-helper cell mediation (PWM system). The IFN-gamma showed more potent (2-to 6-fold) stimulatory activities than IFN-alpha.

Induction of Ia antigens on synovial cells by gamma interferon

Gamma interferon (IFN-γ) is a potent inducer of class II MHC antigens (la) in vitro. Enhanced Ia Expression is a characteristic feature of inflamed rheumatoid synovium. We investigated the potential of Ia induction upon non-inflammatory synovial cells under the influences of gamma interferon, alpha interferon and conditional medium from concanavalin A (Con-A) stimulated peripheral blood lymphocytes cultures (Con-A CM), Ia expression on enzyme dispersed cultured synovial cells decreased with time coincident with the loss of macrophage like cells. Addition of gamma interferon induced Ia molecules upon Ia negative synovial cells in a time and dose dependent manner, whereas alpha interferon treatment failed to induced Ia antigen. Con-A CM exerted the ability to induce Ia upon synovial cells. These findings suggest that: (1) Ia antigen expression by synovial tissue is the result of direct T cell influence: (2) non-inflammatory synovium has a potential to modulate Ia molecules under an altered environment.

Changes of plasma angiotensin-converting enzyme activity during hemodialysis

Plasma angiotensin-converting enzyme activity was measured by spectrophotometer in normal subjects and in patients with end stage renal failure, serially during a routine hemodialysis. Patients on maintenance hemodialysis tended to be associated with elevated plasma angiotensin-converting enzyme activity versus normal subjects. Plasma angiotensin-converting enzyme activity was significantly elevated in patients with chronic renal failure after 5 hours of hemodialysis(p<.001). Plasma angiotensin-converting enzyme activity corrected for hemoconcentration was also significantly increased(p<.05). There was a significant correlation between the increase in plasma angiotensin-converting enzyme activity after 5 hours of hemodialysis and the decrease in white blood cell count at one hour of hemodialysis (r = 0.51, p<.05). It is suggested that plasma angiotensin-converting enzyme analysis may prove to be a method for assessing transient pulmonary dysfunction during hemodialysis.

New disposable ERG electrode made of anomalous polyvinyl alcohol gel

We developed a disposable electrode for the electroretinogram made of anomalous polyvinyl alcohol gel. This new hydrogel is a rubber-like elastic with water content 80-90 wt%, but insoluble in water. The elastic electrode plate is approximately 0.3-1.0 mm thick, sterile, flexible, and easily cut to the desired shape. Its low cost permits it to be discarded after use.

The normal c-wave amplitude in rabbits

We examined some of the problems arising when c-waves are employed in pharmacological experiments with pigmented rabbits. The cyclic variations of the c-wave are smaller in rabbit than in other species. Under our experimental conditions the c-wave amplitudes in some rabbits reached an equilibrium under intermittent stimuli, while in others they increased with time and did not reach a constant level within 3 h. The c-wave amplitude varied with the standing potential during dark adaptation. However interindividual variations made it difficult to standardize the c-waves by this change. Since the c-wave amplitudes of the right and left eyes were similar, the contralateral eye should be used as a control when drugs are administered topically. Interindividual variations of the c-wave amplitude were smaller under dim light. This method is useful in chronic pharmacological experiments when drugs are administered systemically.