Isolated left coronary ostial stenosis--a case report

A patient with isolated left coronary ostial stenosis proved by coronary angiography is presented. Isolated left coronary ostial stenosis is a rare condition of unknown etiology. Unique clinical and angiographic profiles are discussed in detail with a review of the literature, along with a suggestion of a natural history distinct from that usually seen in atherosclerotic coronary diseases.

Management of painful caliceal stones by extracorporeal shock wave lithotripsy

One hundred and seven patients with caliceal stones causing flank pain were treated by extracorporeal shock wave lithotripsy (ESWL), followed up and reviewed. The total stone-free rate 3 months after ESWL was 38.8%. The total pain-free rate was 50.5%. The pain-free rate was 85% in the stone-free group and 29% in the group with residual stones. No significant differences between the stone-free rate and the duration of pain or age was noted. Patients with abnormal intravenous pyelography (IVP) had a lower stone-free rate than patients with normal IVP (16 vs. 45%, p less than 0.05). The complications included: 6 cases of stone street formation with spontaneous passage; 1 case of stone street formation needing percutaneous nephrolithotomy for drainage; 1 perirenal hematoma; 9 cases of severe colic pain following ESWL; 3 cases of fever following ESWL, and 4 cases of hydronephrosis due to a stone in the ureterovesicle junction. These results show that ESWL is an effective, noninvasive treatment for painful caliceal stones.

Human immunodeficiency virus type 1 (HIV-1) infection a median of 18 months before a diagnostic western blot. Evidence from a cohort of homosexual men

STUDY OBJECTIVE

To study the natural history of human immunodeficiency virus type 1 (HIV-1) infection, we used an in-vitro amplification technique to detect HIV-1 nucleic acid sequences in sequential aliquots of peripheral blood mononuclear cells from homosexual men enrolled in the Multicenter AIDS Cohort Study.

DESIGN AND PATIENTS

Blinded, longitudinal study of 24 homosexual men who were positive for HIV-1 antibodies at a recent follow-up visit.

MEASUREMENTS AND MAIN RESULTS

Coded clinical samples were evaluated using two enzyme-linked immunosorbent assays (whole virus and gp120-gp41 fragment), Western blot, a p24 antigen capture assay, virus cocultivation, and in-vitro amplification of conserved regions from the HIV-1 gag and env open-reading frames. In 20 of the 24 men an HIV-1 enzymatically amplified product was detected before HIV-1 antibody seroconversion: at 42 months before seroconversion in two cases; at 36 months in one case; at 30 months in one case; at 24 months in four cases; at 18 months in eight cases; at 12 months in one case; and at 6 months in three cases (median, 18 months). In the four other men, detection of an HIV-1 enzymatically amplified product was concurrent with confirmation of antibody seroconversion by Western blot.

CONCLUSIONS

There is a long and variable interval between virus acquisition and a diagnostic serum antibody response, perhaps due to the prolonged, persistent infection characteristic of the lentiviruses (family Retroviridae).

Phosphorylation inactivates Escherichia coli isocitrate dehydrogenase by preventing isocitrate binding

Equilibrium binding studies demonstrate that purified Escherichia coli isocitrate dehydrogenase binds isocitrate, alpha-ketoglutarate, NADP, and NADPH at 1:1 ratios of substrate to enzyme monomer. The phosphorylated enzyme, which is completely inactive, is unable to bind isocitrate but retains the ability to bind NADP and NADPH. Replacement of serine 113, which is the site of phosphorylation, by aspartate results in an inactive enzyme that is unable to bind isocitrate. Replacement of the same serine with other amino acids (lysine, threonine, cysteine, tyrosine, and alanine) produces active enzymes that bind both substrates. Hence, the negative charge of an aspartate or a phosphorylated serine at site 113 inactivates the enzyme by preventing the binding of isocitrate.

Phospholipid functional groups involved in protein kinase C activation, phorbol ester binding, and binding to mixed micelles

The specificity of the phospholipid cofactor requirement of rat brain protein kinase C was investigated using Triton X-100 mixed micellar methods. Sixteen analogues of phosphatidylserine were prepared and tested for their ability to support protein kinase C activity, [3H]phorbol 12,13-dibutyrate binding, and protein kinase C binding to mixed micelles. Phosphatidylserinol, -L-serine methyl ester, -N-acetyl-L-serine, -2-hydroxyacetate, -3-hydroxypropionate, and -4-hydroxybutyrate did not activate protein kinase C in mixed micelles containing 2 mol % of sn-1,2-dioleoylglycerol. This indicates that both the carboxyl and amino moieties are important for activation. Phosphatidyl-D-serine and -L-homoserine were incapable of supporting full activation; this demonstrates stereospecificity and the importance of the distance between the phosphate and carboxyl and amino moieties. Since 1,2-rac-phosphatidyl-L-serine and 1,3-phosphatidyl-L-serine fully supported protein kinase C activity, the stereochemistry within the glycerol backbone at the interface was not necessary for maximal activation. Neither lysophosphatidyl-L-serine nor 1-oleoyl-2-acetyl-sn-glycero-3-phospho-L-serine supported protein kinase C activity implying that the interfacial conformation is critical to the activation process. The phospholipid dependencies of [3H]phorbol 12,13-dibutyrate binding and of protein kinase C binding to mixed micelles containing sn-1,2-dioleoylglycerol did not mirror those for activation. The data demonstrate that protein kinase C possesses a high degree of specificity with respect to phospholipid activation and implicate several functional groups within the phospho-L-serine polar head group in binding and activation.

Purification and characterization of the sopB gene product which is responsible for stable maintenance of mini-F plasmid

The mini-F plasmid has the trans-acting sopA, sopB genes and the cis-acting sopC DNA which are essential for plasmid partitioning. In this paper, we report the purification of the sopB gene product from extracts of cells harboring a pBR322 derivative carrying the sopB gene. The purity of the final preparation was more than 95%, as determined by densitometry. The amino acid sequence of the amino-terminal region of the protein for the 17 residues identified was identical to that predicted from the DNA sequence of the sopB gene. Therefore, it was concluded that the protein was the sopB gene product. Using anti-SopB serum, the SopB protein was detected in the cell lysates of F+, F', and Hfr strains. The SopB protein bound to the plasmid DNA of a pBR322 derivative carrying the sopC DNA segment, but not to the vector plasmid pBR322.

Identification and nucleotide sequence of attachment site of the Cflt filamentous phage from Xanthomonas campestris pv. citri

It has been reported that the attachment site on the phage attP is located from 69.2 to 73.8 min on Cflt RF DNA. KpnI and PstI were used, which cut respectively at 67.2 and 72.6 min of Cflt RF DNA. A 0.54 kb fragment containing attP was obtained. For isolation of the right (attR) and left (attL) junctions of prophage and host chromosomal DNA, lysogen DNA was digested with HindIII and used to prepare a recombinant plasmid library. With Cflt RF DNA as a probe, three types of recombinant plasmids respectively containing inserts of 1.7, 4.3 and 2.8 kb DNA fragments were obtained. Since 1.7 kb represents the internal HindIII fragment of Cflt, 2.8 kb were from the junctional regions of prophage and host chromosomal DNA. Further analysis of restriction fragment patterns suggested that the 2.8 kb fragment contains attR, while the 4.3 kb fragment contains attL. To isolate the attachment site on the host bacteria (attB), recombinant plasmids constructed from HindIII DNA fragments of uninfected cells are screened by using molecular probes prepared from the host DNA sequences immediately adjacent to the prophage in the lysogenic host chromosomal DNA. A 1.45 kb fragment was obtained. Further analysis with HindIII site on this fragment established that it represents attB. The DNA nucleotide sequences of attP, attB attR and attL were determined. All of them contain a common 15 nucleotide core with the sequence of 5'-TATACATTATGCGAA-3'. The common core region of the recombination site shows two inverted-repeat DNA sequence.

A case of hyperinfection with strongyloides stercoralis in an immunosuppressed patient

We experienced a case of hyperinfection with strongyloides stercoralis in a 64-year-old housewife who complained of severe epigastric pain associated with nausea, vomiting and general weakness for the period of one month. She received corticosteroid therapy for several months because of arthritis prior to admission. The diagnosis was confirmed by examination of gastroduodenal juice and gastrofiberoscopic biopsy. Stool examinations disclosed an abundance of the adult form of strongyloides stercoralis. Albendazole was given for treatment. The patient expired on the 79th hospital day.

Cross-sectional study of reverse transcriptase-inhibiting antibody as a marker of acquired immune deficiency syndrome

A cross-sectional study of 128 individuals infected with human immunodeficiency virus type 1 (HIV-1) was conducted to determine the correlation of reverse transcriptase-inhibiting (RTI) antibody to clinical disease. Thirty-two individuals were studied in each of four clinical groups: asymptomatic individuals, those with persistent generalized lymphadenopathy, those with acquired immune deficiency syndrome (AIDS)-related complex, and those with AIDS. Our study showed that 78% of asymptomatic individuals, 53% of those with persistent generalized lymphadenopathy, 50% of those with AIDS-related complex, and only 25% of those with AIDS have RTI antibody. Concurrent measurement of measles antibody level was used as an indicator of the immune status of these individuals. Measles antibody did not decline in persons with clinical disease, but asymptomatic individuals had lower antibody titers, possibly due to hypergammaglobulinemia associated with advanced HIV infection. These results indicate that more HIV-infected asymptomatic individuals than symptomatic individuals have RTI antibody. This suggests either that the RTI antibody level decreases with the progression of disease in HIV infection or that symptomatic individuals do not produce RTI antibody. The presence or absence of RTI antibody can thus be used as a marker of advanced disease.

The clinical usefulness of serum fructosamine and HbAlc in patients with NIDDM

To evaluate the clinical values of serum fructosamine and HbAlc, serum fructosamine and HbAlc were assessed in 50 normal controls and 36 patients with NIDDM (non-insulin-dependent diabetes mellitus). And we studied 10 patients selected at random among the 36 patients with NIDDM. The values of serum fructosamine and HbAlc in controls were 2.1 mmol/L and 5.3%, respectively. The levels of serum fructosamine and HbAlc were significantly higher in NIDDM patients (3.27 mmol/L and 8.8%, respectively, p less than 0.005) compared with those in the controls. The serum fructosamine was significantly correlated with fasting plasma glucose and HbAlc (r = 0.78, p less than 0.78, p less than 0.001; r = 0.76, p less than 0.005, respectively). Also, in retrograde study, serum fructosamine concentration had a significant correlation to fasting plasma glucose determined 2 weeks before (r = 0.72, p less than 0.002), and 4 weeks before (r = 0.54, p less than 0.005). It is concluded that serum fructosamine measurement may be useful in monitoring short-term control of plasma glucose in patients with NIDDM.

Testicular atrophy in homosexual AIDS patients: an immune-mediated phenomenon?

An immunopathologic analysis of the testes of 20 homosexual acquired immune deficiency syndrome (AIDS) patients was performed to investigate the hypothesis that the testicular atrophy of these patients represents an immune-mediated process. The findings were compared to those in a control group of heterosexual men without AIDS. The testes of the homosexual AIDS patients showed an overall lower degree of spermatogenesis with more prominent interstitial inflammation and thickening of the tubular basement membrane. However, direct immunofluorescence and immunoperoxidase studies failed to demonstrate significant differences in the prevalence of immune complex deposits along the tubular basement membrane in the two study groups. No electron-dense deposits were demonstrated in cases examined ultrastructurally. Therefore, this study does not support the hypothesis that the testicular atrophy of homosexual AIDS patients is a manifestation of autoimmune orchitis. Further studies are needed to elucidate the pathogenesis of the testicular atrophy in AIDS, as this appears to be a specific manifestation of the disease.

Human immunodeficiency virus type 1 infection in homosexual men who remain seronegative for prolonged periods

Infection with the human immunodeficiency virus type 1 (HIV-1), as demonstrated by viral cultures, has been described in some patients before antibodies to HIV-1 can be detected, but the duration and frequency of such latent infections are uncertain. We selected prospectively a cohort of 133 seronegative homosexual men who continued to be involved in high-risk sexual activity, and we cultured 225 samples of their peripheral-blood lymphocytes, using mitogen stimulation to activate the integrated HIV-1 genome. HIV-1 was isolated in blood samples from 31 of the 133 men (23 percent), 27 of whom have remained seronegative for up to 36 months after the positive culture. The other four men seroconverted 11 to 17 months after the isolation of HIV-1. In three of them, we studied cryopreserved lymphocytes obtained earlier, using the polymerase chain reaction to amplify small amounts of viral DNA, and we demonstrated that HIV-1 provirus had been present 23, 35, and 35 months before seroconversion. We conclude that HIV-1 infection in homosexual men at high risk may occur at least 35 months before antibodies to HIV-1 can be detected. A prolonged period of latency in such infections may be more common than previously recognized; the degree of infectiousness during such periods is unknown.

Hazards of angioscopic examination: documentation of damage to the arterial intima

The fiberoptic scope is increasingly used in the coronary and peripheral arteries to quantitate the degree and type of arterial obstructive disease and to inspect the results of procedures such as bypass grafting and laser irradiation of obstructive lesions. Since little is known about this instrument's potential complications, we passed a variety of fiberoptic scopes (1.8 to 3.6 mm outer diameter) in fresh postmortem pig coronary arteries and live monkey and canine peripheral arteries, and observed the intraluminal anatomy through the angioscope. No perforations were created, but ridges rising from the vascular luminal surface, avulsion of the endothelial lining, and small flaps attached at one end to the vessel wall were observed. Histologically, subintimal and medial tears were evident. Inserting large diameter scopes or making frequent passes (10 to 100) in coronary arteries increased intravascular injury. The use of small diameter flexible scopes or infrequent passes (less than 10) in the larger iliac and femoral arteries of live monkeys and dogs resulted in a lower frequency of myointimal sloughing or flap formation. Current fiberoptic scopes are not ideal angioscopes; they have a rigid tip, cannot be steered adequately, and are relatively stiff, resulting in a high probability of intraluminal injury, especially when used in small tortuous arteries. To decrease the risk of such injury, we recommend gentle manipulations while passing the scope and use of the smallest diameter scope possible. We further suggest limited use of the fiberscope, or at least limiting the number of passes in small vessels such as coronary arteries.

Multiple symmetric lipomatosis

Multiple symmetric lipomatosis (MSL) is an extremely uncommon disorder. In the medical literatures about 200 cases have been reported. MSL is not associated with other generalized lipomatous disorders, nor are these patient to be necessarily obese. The cause of MSL is unknown. The disorder usually occurs in middle-aged males and there is frequently a history of alcoholism. Some instances of familial occurrence have been reported, but the majority of cases are sporadic. Two cases of MSL are presented.

Neocortical transplants in the micrencephalic rat brain: morphology and behavior

Normal fetal (E18) neocortical tissue transplanted into the hypoplastic posterior neocortex of infant (10 +/- 2-day-old) rats with transplacentally induced micrencephaly developed into very large, healthy, and permanent transplants. Although the cellular organization within the transplants rarely resembled that of normal rat neocortex, the transplants formed a broad area of interface with the host brain and established fiber connections with it. When tested at 2 months and 1-year-of-age, the presence of the transplant had no significant effect on the typically abnormal performance of micrencephalic rats on two tests of unspecific function, open field activity and maze learning. However, a small group of micrencephalic rats in whom the transplant tissue had failed to fill in the small brain lesions inescapably inflicted during surgery, showed greater behavioral deficits than the micrencephalic controls, suggesting that the transplant had corrected the lesion effect.

Effect of hyperthermia on cis-diamminedichloroplatinum(II) (rhodamine 123)2[tetrachloroplatinum(II)] in a human squamous cell carcinoma line and a cis-diamminedichloroplatinum(II)-resistant subline

The effect of concomitant hyperthermia on the cytotoxicities of cis-diamminedichloroplatinum(II) (CDDP), a newly synthesized drug, Pt(Rh-123)2, and its chemical components, K2PtCl4 and rhodamine 123, was examined in vitro in a squamous cell tumor line of human origin (SCC-25) and in a CDDP-resistant subline (SCC-25/CP). No difference in the cytotoxicity of hyperthermia alone was observed between these cell lines. The dose-dependent cytotoxicities of 1-h exposures to CDDP and Pt(Rh-123)2 were markedly increased at 42 degrees C and 43 degrees C in comparison to 37 degrees C, and this effect was of the same magnitude in both cell lines (enhancements of approximately 1.5 logs at 42 degrees C and 2.5 logs at 43 degrees C for CDDP and 1.5 logs at 42 degrees C and greater than 3 logs at 43 degrees C for Pt(Rh-123)2). The use of hyperthermia with CDDP, however, did not lower survivals in the SCC-25/CP cells even to the levels seen in the parent line at 37 degrees C. The cytotoxicities of K2PtCl4 and rhodamine 123 were essentially the same in the CDDP-sensitive and -resistant cells at all temperatures tested. The magnitude of the temperature effect was significantly greater for Pt(Rh-123)2 than for its chemical components. No significant effect on CDDP or Pt(Rh-123)2 accumulation was observed at 42, 43, 44 or 45 degrees C in either cell line. DNA lesions, measured by alkaline elution, were significantly enhanced for CDDP in the SCC-25 cells at 42 degrees C. These results suggest that treatment with hyperthermia and either CDDP or Pt(Rh-123)2 should result in supraadditive anti-tumor effects, although the efficacy of CDDP plus hyperthermia will be significantly less once resistance to CDDP has developed. Since resistance to CDDP does not imply cross-resistance to Pt(Rh-123)2, and since the effect of hyperthermia is somewhat greater for Pt(Rh-123)2 than for CDDP at 43 degrees C, Pt(Rh-123)2 may be more selectively toxic to tumor cells when used with local hyperthermia versus normal cells outside the treated area, especially if resistance to CDDP has already developed.

Effect of incubation temperature, ageing, and bisulfite content of unsupplemented Brucella agar on aerotolerance of Campylobacter jejuni

A mutant strain of Campylobacter jejuni ATCC 29428 was isolated that grows on unsupplemented Brucella agar at O2 levels as high as 21% at 37 degrees C. While measuring the degree of aerotolerance of this mutant on unsupplemented Brucella medium and comparing it with that of the wild type, we found considerable variation among our estimates. As measured by colony counts on unsupplemented Brucella agar incubated at various oxygen levels, the degree of aerotolerance was affected by incubation temperature and the age of the medium. Aerotolerance was consistently higher on plates incubated at 42 degrees C than at 37 degrees C. When the commercial dehydrated Brucella medium that was used to prepare the Brucella agar was stored in a beaker for 2.5 months, the degree of aerotolerance of C. jejuni was decreased. Addition of 0.01% sodium bisulfite reversed this inhibition. Storage of bottles of hydrated Brucella agar for 1.5 months also resulted in a decreased aerotolerance; again, in addition of 0.01% bisulfite reversed the effect. Aerotolerance was greatly decreased when Brucella agar was prepared from all its individual components except 0.01% bisulfite. The results indicate that the bisulfite component of Brucella agar deteriorates during storage of the dehydrated and hydrated media, and that this deterioration can affect measurements of aerotolerance.

Computerized quality control of radioimmunoassay in Korea

Automated data processing and quality control of radioimmunoassays offer not only increased speed but also a more thorough and statistically rigorous analysis of results. An external quality assessment scheme for serum thyroxine, triiodothyronine and thyroid stimulating hormone (TSH) assays was performed in five nuclear medicine laboratories in Korea to compare with the assay performances of the World Health Organization Radioimmunoassay Program. The required radioimmunoassay kits were supplied through the International Atomic Energy Agency (IAEA). We have determined the weighted root mean squared error, and variance ratio as the indices of standard curve and also the average batch coefficient of variation (ABCV) as the parameters of response error relationship curve and precision profile. There was a good fit for the triiodothyronine assay, but 3 of 5 laboratories showed possible bad fit in the T4 and TSH assay systems. The ABCV was less than 5 percent for the T3 and T4 assay system, however for the TSH system, only 1 laboratory showed the ABCV value of less than 5 percent. We have also calculated the within batch variation (drift) and between laboratory variations.

Immunoglobulin inclusions in Burkitt's-like malignant lymphoma: a case report

A case of acquired immune deficiency syndrome (AIDS)-related Burkitt's-like lymphoma (BLL), demonstrating an as yet unreported occurrence of intracytoplasmic immunoglobulin inclusions, is reported. Histologic, immunocytochemical, and ultrastructural features are described with a review of the literature on signet-ring cell lymphoma.

Deoxycytidylate hydroxymethylase: purification, properties, and the role of a thiol group in catalysis

Deoxycytidylate (dCMP) hydroxymethylase from Escherichia coli infected with a T-4 bacteriophage amber mutant has been purified to homogeneity. It is a dimer with a subunit molecular weight of 28,000. Chemical modification of the homogeneous enzyme with N-ethylmaleimide (NEM) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) leads to complete loss of enzyme activity. dCMP can protect the enzyme against NEM inactivation, but the dihydrofolate analogues methotrexate and aminopterin alone do not afford similar protection. Compared to dCMP alone, dCMP plus either methotrexate or aminopterin greatly enhances protection against NEM inactivation. DTNB inactivation is reversed by dithiothreitol. For both reagents, inactivation kinetics obey second-order kinetics. NEM inactivation is pH dependent with a pKa for a required thiol group of 9.15 +/- 0.11. Complete enzyme inactivation by both reagents involves the modification of one thiol group per mole of dimeric enzyme. There are two thiol groups in the totally denatured enzyme modified by either NEM or DTNB. Kinetic analysis of NEM inactivation cannot distinguish between these two groups; however, with DTNB kinetic analysis of 2-nitro-5-thiobenzoate release shows that enzyme inactivation is due to the modification of one fast-reacting thiol followed by the modification of a second group that reacts about 5-6-fold more slowly. In the presence of methotrexate, the stoichiometry of dCMP binding to the dimeric enzyme is 1:1 and depends upon a reduced thiol group. It appears that the two equally sized subunits are arranged asymmetrically, resulting in one thiol-containing active site per mole of dimeric enzyme.

Comparable sensitivities for detection of human immunodeficiency virus by sensitive reverse transcriptase and antigen capture enzyme-linked immunosorbent assays

The sensitive overnight reverse transcriptase and the antigen capture enzyme-linked immunosorbent assays were tested for their ability to detect human immunodeficiency virus. The two assays were able to quantitate as few as 75 to 130 virus particles. Thus, both tests offer similar sensitivities for determining the presence of the virus.

Bovine liver dihydropyrimidine amidohydrolase: pH dependencies of the steady-state kinetic and proton relaxation rate properties of the Mn(II)-containing enzyme

The essential Zn(II) in bovine liver dihydropyrimidine amidohydrolase (DHPase) was removed by incubation with 2,6-dipicolinic acid and replaced with Mn(II). Electron paramagnetic resonance studies of Mn(II) binding show that there are four binding sites per tetramer, and the dissociation constant at pH 7.5 is 13.5 microM. The substitution of Mn(II) for Zn(II) increases the specific activity of the enzyme approximately sixfold but has only a small effect (twofold increase) on the Km for 5-bromo-5,6-dihydrouracil (BrH2Ura). The pH dependence of the catalytic properties of Mn(II)-DHPase is the same as for the Zn(II) enzyme (Lee, M., Cowling, R., Sander, E., and Pettigrew, D. (1986) Arch. Biochem. Biophys. 248, 368-378). The pH dependence is well described in terms of the ionization of a single group with a pK of about 6 in the free enzyme. The ionization of this group is required for catalytic activity. The substitution of Mn(II) for Zn(II) does not affect the pH dependence of DHPase catalysis and therefore strongly suggests that the ionizable group is an amino acid residue at or near the active site, rather than a metal-bound water molecule. The pH dependence of the enhancement of the paramagnetic effect of the DHPase-Mn complex on the relaxation rate of the solvent water protons also is well described in terms of the ionization of a single group with a pK of about 6. Ionization of the group which is involved in catalysis also perturbs the environment of the bound Mn(II). The ionization of the active site group does not affect the number of exchangeable water molecules but does affect the symmetry of the environment of the bound Mn(II) and its electron relaxation.