Changing seroepidemiology of hepatitis A virus infection between two regions in Taiwan differing in socioeconomic status

In Taiwan, hepatitis A virus (HAV) infection is hyperendemic, and prior to the late 1970s more than 85% of the population was infected by 15 years of age. In this study, the prevalence of HAV infection in two regions of Taiwan with differing standards of living is evaluated. Serum antibody to HAV (anti-HAV) was determined by enzyme immunoassay. A total of 4,218 subjects under the age of 16 years were enrolled. The first group of 1,581 subjects were residents of the prosperous western plain region where the socioeconomic status and living environment have improved greatly in the past 20 years; the second group of 2,637 subjects were aborigines inhabiting the eastern and central mountain regions where improvement in the standard of living lags far behind the western region. All serum samples were collected in 1991 except for 1,100 samples collected in 1989 from elementary and junior middle school students in Tainan city. The prevalence of HAV infection was 11.9% for the western region and 81.0% for the eastern and central regions. In the eastern and central regions, 80% of the subjects had been infected with HAV before the age of six years, in contrast to 0% in the western region. By the age of 13 years, only 6% of the subjects were infected in the western region; however 97% had been infected in the eastern and central regions. Among children under the age of 10 years, only 10.6% (10/94) of the IgM-anti-HAV positive cases had clinical symptoms. These findings indicate that HAV infection has a close relationship with socioeconomic status and environmental sanitation.

Normal human mesothelial cells and mesothelioma cell lines express insulin-like growth factor I and associated molecules

Insulin-like growth factor (IGF) I has important growth regulatory functions in normal growth and development. IGF-I is also a mitogen for a number of cancer cell lines; however, its autocrine effect has not been well established. In this study, the expression of IGF-I, its receptor, and its major serum-binding protein were examined in 5 normal human mesothelial (NHM) cell samples and 11 pleural mesothelioma cell lines. All NHM cells and mesothelioma cell lines expressed IGF-I, IGF-binding protein 3 (IGFBP-3), and IGF-I receptor mRNA by either Northern blot or reverse transcription polymerase chain reaction analysis. IGF-I (0.136 +/- 0.024 ng/ml, mean +/- SEM) and IGFBP-3 (18.5 +/- 3.2 ng/ml) proteins were readily detected in the conditioned medium of mesothelioma cell lines but were not greater than corresponding measurements in that of NHM cells (IGF-I, 0.120 +/- 0.080 ng/ml; IGFBP-3, 15.9 +/- 1.3 ng/ml). Exogenous recombinant IGF-I stimulated cell proliferation of NHM cells, demonstrating the presence of a functional IGF-I receptor. Our results suggest that IGF-I may function as an autocrine growth stimulus in normal proliferating mesothelial cells, which may contribute to their malignant transformation.

Increased biliary transferrin excretion following parenteral aluminium administration to rats

Aluminium accumulates in the livers of patients receiving either parenteral nutrition or haemodialysis. When given parenterally to rats, aluminium causes cholestasis. However, the mechanism of hepatic aluminium uptake and the fate of aluminum in the liver are poorly understood. We examined the effect of parenteral aluminium administration on biliary excretion of transferrin, the major circulating aluminum-binding protein. Male Wistar rats were given parenterally aluminum 5 mg/kg/day for 1-14 days. Bile was collected for 3 hr at the end of the study period. Biliary total protein concentration and IgA/total protein were unaffected by up to 14 days of parenteral aluminium administration. However, biliary transferrin excretion increased with duration of aluminum administration up to five-fold by day 14. Biliary transferrin concentration and transferrin/total protein was higher in aluminum treated rats than controls after 7 and 14 days of study. Hepatic aluminum concentration reached a maximum after 4 days of parenteral aluminum administration, at which time serum bile acid and alanine amino transferase values were not different from controls. Since biliary transferrin is normally derived from the serum, it is likely that aluminum promotes hepatocellular uptake of transferrin and that aluminum enters the hepatocyte bound to transferrin. We postulate that transferrin may direct aluminum to intracellular sites where its toxic effects would be minimized.

Glutathione S-transferase pi facilitates the excretion of arsenic from arsenic-resistant Chinese hamster ovary cells

We have previously demonstrated that glutathione S-transferase pi (GST pi) is overexpressed in SA7 cells, an arsenic resistant cell line derived from Chinese hamster ovary (CHO) cells. Our present results show that SA7 cells accumulate less arsenic than parental CHO cells and partially revertant SA7N cells. The lower levels of arsenic accumulation in SA7 cells resulted from their faster excretion rates. However, the excretion of arsenic from SA7 cells was significantly inhibited by the GST inhibitors ethacrynic acid and Cibacron blue. Furthermore, when GST pi levels in SA7N cells were re-elevated by zinc sulfate pretreatment, arsenic accumulation decreased and arsenic excretion increased to levels similar to those in SA7 cells. These results suggest that GST pi can facilitate the excretion of arsenic. Such facilitation by GST pi is unlikely to be associated with multi-drug resistant P-glycoprotein, since no overexpression of P-glycoprotein was detected in SA7N and SA7 cells.

Mechanisms of stimulation of interleukin-1 beta and tumor necrosis factor-alpha by Mycobacterium tuberculosis components

The granulomatous immune response in tuberculosis is characterized by delayed hypersensitivity and is mediated by various cytokines released by the stimulated mononuclear phagocytes, including tumor necrosis factor-alpha (TNF alpha) and IL-1 beta. We have demonstrated that Mycobacterium tuberculosis cell wall component lipoarabinomannan (LAM), mycobacterial heat shock protein-65 kD, and M. tuberculosis culture filtrate, devoid of LPS as assessed by the Amebocyte Lysate assay, stimulate the production of TNF alpha and IL-1 beta proteins and mRNA from mononuclear phagocytes (THP-1 cells). The effect of LAM on the release of these cytokines was specific, as only LAM stimulation was inhibited by anti-LAM monoclonal antibody. Interestingly, we found that LAM and Gram-negative bacterial cell wall-associated endotoxin LPS may share a similar mechanism in their stimulatory action as demonstrated by inhibition of TNF alpha and IL-1 beta release by monoclonal antibodies to CD14. Anti-CD14 monoclonal antibody MY4 inhibited both TNF alpha and IL-1 beta release with LAM and LPS but no effect was observed with other mycobacterial proteins. An isotype antibody control did not inhibit release of cytokines under the same experimental conditions. M. tuberculosis and its components upregulated IL-1 beta and TNF alpha mRNAs in THP-1 cells. Nuclear run-on assay for IL-1 beta demonstrated that LAM increased the transcription rate. The induction of IL-1 beta was regulated at the transcriptional level, in which these stimuli acted through cis-acting element(s) on the 5' flanking region of the IL-1 beta genomic DNA. M. tuberculosis cell wall component LAM acts similarly to LPS in activating mononuclear phagocyte cytokine TNF alpha and IL-1 beta release through CD14 and synthesis at the transcriptional level; both cytokines are key participants in the host immune response to tuberculosis.

Pedicle fixation: an adjuvant for the treatment of thoracolumbar metastases

For a long time, radiotherapy was considered as the best treatment for spinal metastases. However, radiotherapy alone could not resolve the problem of pathological fracture which is an important complication of spinal metastases. In this paper, we introduce pedicle fixation system as an adjuvant to radiotherapy to treat eight patients with thoracolumbar metastases. The result was encouraging that all the patients achieved spinal stabilisation and all but one had immediate postoperative relief of back pain. The operation time was short and none of the patients required a blood transfusion. Tissue diagnosis was possible through this approach.

Enhanced IL-1 beta and tumor necrosis factor-alpha release and messenger RNA expression in macrophages from idiopathic pulmonary fibrosis or after asbestos exposure

Idiopathic pulmonary fibrosis (IPF) and asbestosis are fibrotic interstitial lung diseases characterized by alveolar wall fibrosis with accumulation of extracellular matrix, interstitial remodeling, and increased numbers of activated alveolar macrophages. Animal models and in vitro studies have shown that macrophage cytokines, namely IL-1 beta and TNF-alpha, play significant roles in the development of fibrosis. We found significant increases for TNF-alpha release in both diseases (p < 0.01) and a significant increase for IL-1 beta release in asbestosis compared to normal controls (p < 0.01). Also, the mRNA expression of these cytokines was increased in alveolar macrophages from patients with IPF or asbestosis compared with normals. The level of TNF-alpha release in macrophage supernatants correlated with the number of neutrophils per milliliter bronchoalveolar lavage fluid returned. Chrysotile, crocidolite, amosite asbestos, and silica stimulated IL-1 beta and TNF-alpha release and up-regulated their respective mRNA in macrophages or monocytes. To evaluate the role of IL-1 beta and TNF-alpha in the accumulation of extracellular matrix, we studied collagen types I and III and fibronectin gene expression in human diploid lung fibroblasts after short term (2 h) serum-free exposure to recombinant cytokines. Both cytokines up-regulated these genes 1.5- to 3.6-fold. These cytokines have the potential to influence the remodeling and fibrosis observed in the lower respiratory tract in IPF and asbestosis.

Enhanced IL-1 beta and tumor necrosis factor-alpha release and messenger RNA expression in macrophages from idiopathic pulmonary fibrosis or after asbestos exposure

Idiopathic pulmonary fibrosis (IPF) and asbestosis are fibrotic interstitial lung diseases characterized by alveolar wall fibrosis with accumulation of extracellular matrix, interstitial remodeling, and increased numbers of activated alveolar macrophages. Animal models and in vitro studies have shown that macrophage cytokines, namely IL-1 beta and TNF-alpha, play significant roles in the development of fibrosis. We found significant increases for TNF-alpha release in both diseases (p &lt; 0.01) and a significant increase for IL-1 beta release in asbestosis compared to normal controls (p &lt; 0.01). Also, the mRNA expression of these cytokines was increased in alveolar macrophages from patients with IPF or asbestosis compared with normals. The level of TNF-alpha release in macrophage supernatants correlated with the number of neutrophils per milliliter bronchoalveolar lavage fluid returned. Chrysotile, crocidolite, amosite asbestos, and silica stimulated IL-1 beta and TNF-alpha release and up-regulated their respective mRNA in macrophages or monocytes. To evaluate the role of IL-1 beta and TNF-alpha in the accumulation of extracellular matrix, we studied collagen types I and III and fibronectin gene expression in human diploid lung fibroblasts after short term (2 h) serum-free exposure to recombinant cytokines. Both cytokines up-regulated these genes 1.5- to 3.6-fold. These cytokines have the potential to influence the remodeling and fibrosis observed in the lower respiratory tract in IPF and asbestosis.

Intraoperative high-dose rate interstitial irradiation of hepatic metastases from colorectal carcinoma. Results of a phase I-II trial

BACKGROUND

Resection of liver metastases from colorectal carcinoma can be curative. Unresectable but liver-confined metastases might be ablated by high-dose radiation with a similar curative result.

METHODS

At Georgetown University Hospital, 22 patients with unresectable hepatic metastases from colorectal carcinoma underwent 24 interstitial irradiation procedures at laparotomy in a Phase I-II study. A single dose was administered with a high-dose rate iridium-192 afterloader. Dose to the tumor periphery was 20 Gy, 25 Gy, and 30 Gy in 13, 9, and 2 procedures, respectively.

RESULTS

No acute or chronic radiation toxicity has occurred at a median follow-up of 11 months. Median actuarial local control at irradiated sites was 8 months, with 26% actuarial local control at 26 months by computed tomography (CT) or magnetic resonance imaging (MRI) scanning. In the two patients undergoing two procedures each, a second biopsy of previously irradiated areas demonstrated tumor eradication.

CONCLUSIONS

This innovative, radical approach to unresectable colorectal hepatic metastases proved safe. Additional study is needed to determine whether interstitial irradiation is as effective as surgical resection, or whether it alters the natural history of the disease or longevity.

Protection of a rat tracheal epithelial cell line from paraquat toxicity by inhibition of glucose-6-phosphate dehydrogenase

Transformed rat tracheal epithelial cells (U2) were found to be 3.6-fold more sensitive than lung fibroblasts (RLF) to paraquat. Although the toxic effects of paraquat are associated with the generation of very active superoxides, U2 cells contained higher levels of superoxide dismutase and catalase than RLF cells. On the other hand, the specific activities of both NADPH-cytochrome c reductase and glucose-6-phosphate dehydrogenase (G6DP) were 3- to 4-fold higher in U2 cells than in RLF cells. Treatment with dehydroepiandrosterone (DHEA) and epiandrosterone (EPI), G6PD inhibitors, significantly decreased the intracellular NADPH and protected U2 cells from paraquat toxicity. Since DHEA and EPI treatment did not affect the uptake of paraquat, our results suggest that paraquat sensitivity may depend on the redox cycling-associated activities of paraquat.

Evidence for biosynthesis of plasmenylcholine from plasmenylethanolamine in HL-60 cells

Both [3H]plasmenylethanolamine and [3H]plasmenylcholine were produced from substrates of [3H]alk-1-enylglycerol and [3H]alk-1-enyllysoglycerophosphoethanolamine by intact HL-60 cells. Molecular species analysis of the [3H]plasmenylcholine and [3H]plasmenylethanolamine formed indicated the major portion of plasmenylcholine originates from plasmenylethanolamine by a series of reactions catalyzed by phospholipase A2, lysophospholipase D, acyltransferase, phosphohydrolase, and cholinephosphotransferase. However, a significant but much smaller portion of the plasmenylcholine appeared to be synthesized from plasmenylethanolamine via a direct base-exchange or a coupled phospholipase C/cholinephosphotransferase reaction.

Primary structure of three distinct isoabrins determined by cDNA sequencing. Conservation and significance

A family of toxic proteins, the isoabrins, which possess N-glycosylase activity toward eukaryotic 28 S r-RNA, may have potential use in cancer chemotherapy. By polymerase chain reaction techniques, cDNA clones of three isoabrins, carrying A and B-chain sequences, were isolated and their nucleotide sequences were determined. The isoabrins consist of an A-chain comprised of 250 of 251 amino acids, followed by a 10 amino acid linker and a B-chain of 267 amino acids. There is substantial conservation in the B-chain of the three isoabrins, with less than six amino acid substitutions, whereas as many as 46 amino acid substitutions occur in the A-chains. Based on the relationships between the biological activities and the putative amino acid sequences of the isoabrins, three isoabrins, abrin-a, -b and -d, could be identified and the potential epitope of immunological response of these isoabrins could be assigned.

Expression of P-glycoprotein and glutathione-S-transferase in recurrent lymphomas: the possible role of Epstein-Barr virus, immunophenotypes, and other predisposing factors

PURPOSE

We previously have reported the poor prognoses of recurrent peripheral T-cell lymphoma (PTCL) and Epstein-Barr virus (EBV)-associated PTCL (J Clin Oncol 7:725-731, 1989; Blood 77:799-808, 1991). To study the role that drug resistance plays in this scenario, we conducted a retrospective study of 23 adult patients.

PATIENTS AND METHODS

All patients had recurrent lymphoma tissue available for immunophenotyping and screening for the existence of EBV DNA in tumor cells by Southern blot analysis and in situ hybridization. Expression of a multidrug resistance P-glycoprotein ([P-gp]mdr-1) and a glutathione redox cycle-related glutathione-S-transferase pi (GST-pi) was determined by an immunohistochemistry method.

RESULTS

Expression of mdr-1 or GST-pi was found in 11 (48%) and 12 (52%) cases, respectively. Most (11 of 12) of the GST-pi expression occurred simultaneously with mdr-1. Prechemotherapy tumor tissues were available in 11 cases; only two (18.2%) of these cases expressed mdr-1. Four (36%) of 11 cases that expressed mdr-1 (mdr-1(+)) and nine (90%) of 10 cases that did not express mdr-1 (mdr-1(-)) responded to second-line chemotherapy (P < .05). The survival-after-recurrence (SAR) curves significantly favored mdr-1(-) recurrent lymphoma (P < .05). The mdr-1 expression was further correlated with the immunophenotype and EBV association. All six cases of EBV-associated lymphoma (PTCL, five cases; Hodgkin's disease, one case) had significant simultaneous expression of mdr-1 and GST-pi in their recurrent tumor tissues.

CONCLUSION

(1) mdr-1 expression is a significant prognostic factor in recurrent lymphomas; (2) high expression of mdr-1 is observed in recurrent EBV-associated PTCL; and (3) GST-pi usually expresses simultaneously with mdr-1 in recurrent lymphomas. The role of EBV in the development of mdr-1 and the biologic significance of the simultaneous expression of mdr-1 and GST-pi in recurrent lymphomas are well worth further exploration.

Glutathione S-transferase pi in an arsenic-resistant Chinese hamster ovary cell line

A glutathione S-transferase (GST) was purified from an arsenic-resistant Chinese hamster ovary cell line, SA7. The SA7 GST was shown to catalyse the conjugation of glutathione and ethacrynic acid, a specific substrate for Pi class GST. Its N-terminal amino-acid sequence has 80% identical residues to that of rat GST P and human GST pi. Thus, the GST purified from SA7 cells belongs to the Pi family. Treatment with Cibacron Blue or ethacrynic acid, which are GST inhibitors, significantly decreased the resistance of SA7 cells to sodium arsenite. On the other hand, pretreatment of SA7N cells, a partial revertant of SA7 cells, with sublethal doses of sodium arsenite, cadmium acetate or zinc sulphate resulted in re-elevation of GST activities and the cells regained the arsenic resistance. The regained arsenic resistance was well correlated with the levels of GST pi which were induced dose-dependently by zinc sulphate. Heat-shock treatment (45 degrees C for 10 min) did not increase GST pi expression or arsenic resistance of SA7N cells. The results indicate that GST pi is possibly involved in the mechanism of arsenic detoxification.

Molecular epidemiology of endemic ciprofloxacin-susceptible and -resistant Enterobacteriaceae

OBJECTIVES

To elucidate the epidemiology of widespread ciprofloxacin resistance in our Veterans Affairs medical center using whole cell DNA analysis.

DESIGN

In vitro study of ciprofloxacin resistant and susceptible Enterobacteriaceae isolated during the course of a clinical epidemiologic study of quinolone resistance.

SETTING

Veterans Affairs Medical Center with acute care and long-term care divisions.

RESULTS

We examined 40 ciprofloxacin-resistant strains of Serratia marcescens, Proteus mirabilis, and Providencia stuartii using restriction endonuclease analysis of whole cell DNA and compared them with concomitantly isolated ciprofloxacin sensitive strains. We sought to determine whether resistant strains were identical to susceptible strains, indicating in vivo emergence of resistant strains from susceptible strains, and whether resistant strains were shared among patients. All 26 ciprofloxacin-resistant S marcescens isolates shared a single ecoRI restriction pattern. Multiple patterns were seen in the ciprofloxacin-susceptible S marcescens isolates; however, several isolates had a pattern matching that of the resistant isolates. Similar results were seen among the P mirabilis isolates. Three different ecoRI patterns were found among the ciprofloxacin-resistant P stuartii isolates; none matched those found among the susceptible isolates. The frequency of spontaneous emergence of ciprofloxacin resistance in susceptible S marcescens strains with restriction pattern matching that of the resistant strains was significantly higher than that of nonmatching strains.

CONCLUSIONS

Ciprofloxacin-resistant strains of Enterobacteriaceae became widespread within a short period of time. Resistant strains of S marcescens and P mirabilis arose from endemic susceptible strains. The resistant strain of S marcescens appeared to arise from a susceptible strain with a relatively high frequency of spontaneous ciprofloxacin resistance.

Mutational specificity of chromium(VI) compounds in the hprt locus of Chinese hamster ovary-K1 cells

Chromium(VI) compounds exert their genotoxicity and mutagenicity by complex metabolic reducing pathways that generate a variety of reactive forms of chromium and free radicals. To investigate the molecular nature of chromium-induced mutations, we characterized the entire coding region of the hypoxanthine (guanine) phosphoribosyltransferase (hprt) gene of 27 independent mutants derived from chromium(VI) oxide (CrO3)-treated Chinese hamster ovary-K1 cells, by direct sequencing of PCR-amplified cDNA. Among these mutants, 10 consisted of single base substitutions, five contained two base substitutions, one had four base substitutions, six were splicing mutations, and five exhibited single base pair insertions or deletions. All of the base substitutions and most of the frameshift mutations observed were located at A/T-rich sequences. More than 90% of the base substitutions (22/24) occurred in A.T base pairs. Among them, T-->A and T-->G transversions (18/22) predominated. The mutational hotspots for single and double base substitutions were the 3' thymidine of 5'PuT and thymidines of 5'ATTT sequences respectively. This mutational specificity was also observed in CHO-K1 cells treated with two other chromium(VI) compounds, namely K2Cr2O7 and PbCrO4. Strand bias was noticed in chromium mutagenicity, since 77% of T base substitutions occurred on the non-transcribed strand. This highly sequence-specific mutation spectrum suggests that a particular form of chromium may directly interact with DNA at these hotspot sequences.

Displacement of BrdUrd-induced YY1 by serum response factor activates skeletal alpha-actin transcription in embryonic myoblasts

Muscle-restricted transcription of the skeletal alpha-actin gene is controlled in part by a positive regulator, serum response factor (SRF), and a negative regulator, F-ACT1, which bind competitively to the most proximal serum response element (SRE1). We show here that F-ACT1 is identical to a transcription factor recently cloned and described as YY1, NF-E1, delta, or UCRBP. We found that although the DNA-binding activity of SRF accumulates during myogenesis, that of YY1 diminishes simultaneously. Myoblasts rendered incapable of differentiation by BrdUrd treatment exhibited the highest level of YY1 and the lowest level of SRF activities. Transfected SRF could directly transactivate the skeletal alpha-actin promoter by overcoming the inhibitory effect of BrdUrd-induced YY1. The transactivation depends on intact SRE DNA elements and requires the DNA-binding/dimerization domain of SRF as well as its C-terminal half rich in serines and threonines. Since the functions of YY1 and SRF appear to be developmentally regulated, the convergence of their binding sites upon the SRE constitutes an integrated mechanism whereby temporal and spatial muscle gene expression may be accomplished.

A novel CoA-independent transacetylase produces the ethanolamine plasmalogen and acyl analogs of platelet-activating factor (PAF) with PAF as the acetate donor in HL-60 cells

In this study, we demonstrate the presence of a unique membrane-associated transacetylase that transfers the acetate group from platelet-activating factor (PAF) to lysoplasmalogen (in the presence of EDTA and sodium acetate) with the formation of 1-alk-1-enyl-2-acetyl-sn-glycero-3-phosphoethanolamine (alk-1-enylacetyl-GPE). The identity of alk-1-enylacetyl-GPE was confirmed by acid hydrolysis, phospholipases A2 or C treatment and derivatization by fluorodinitrobenzene. The transacetylase has no requirement for Ca2+, Mg2+, or CoA and a broad pH optimum (7.0-8.0) with Km values of 12.0 microM for PAF and 106.4 microM for lysoplasmalogens. The enzyme activity from the isolated membrane fraction is not changed when whole cells are supplemented with 20:4, induced to differentiate into granulocytes, or treated with ionophore A23187. Radyllyso-sn-glycero-3-phosphocholine (GPC), radyllyso-GPE, acyllyso-sn-glycero-3-phosphoserine (GPS), acyllyso-sn-glycero-3-phosphoinositol (GPI), alkyllyso-sn-glycero-3-phosphate (GP), acyllyso-GP, or cis-9-octadecen-1-ol can also serve as acetate acceptors, whereas alkylglycerol, acylglycerol, or cholesterol are inactive. Differences in substrate acceptor specificity, sensitivity toward phenylmethylsulfonyl fluoride, and response to temperature suggest that the CoA-independent transacetylase and the CoA-independent transacylase that transfers long-chain acyl moieties are two separate enzymes. With intact differentiated HL-60 cells, [3H]acetate from [3H]PAF can be incorporated into alk-1-enylacetyl-GPE in the presence of ionophore A23187, but not in its absence. Moreover, phospholipase A2 inhibitors (p-bromophenacyl bromide and mepacrine) block the transacetylation process in whole cell system. These results indicate the production of alk-1-enyllyso-GPE is a rate-limiting factor for the subsequent transacetylation step during cell activation. We conclude that the transacetylase may participate in the biosynthesis of ethanolamine plasmalogen and acyl analogs of PAF, in vivo, fine-tuning of PAF biological responses, and cross-talk between de novo and remodeling pathways of PAF biosynthesis.

Legionella pneumophila in residential water supplies: environmental surveillance with clinical assessment for Legionnaires' disease

Although cases of community-acquired Legionnaires' disease have been epidemiologically linked to residential water supplies, the risk of acquiring Legionnaires' disease from exposure to Legionella pneumophila in residential water systems is uncertain. The residential water supplies of 218 members of the American Legion in six different geographical areas in Pittsburgh were cultured for L. pneumophila. Residents of the homes provided a recent medical history and a blood sample for detection of antibodies to legionella. A urine sample for legionella urinary antigen testing was also requested from individuals residing in legionella-positive homes and individuals with a positive antibody test. Six percent (14/218) of the homes yielded L. pneumophila (range within six areas 0-22%). Lower hot water tank temperature was significantly associated with legionella positivity (P less than 0.01). Analysis of water samples for mineral content showed no association between legionella positivity and concentrations of calcium and magnesium. Water samples from the area where 22% of the homes surveyed were positive for legionella had a higher iron content than water samples from the other areas tested. None of the individuals residing in legionella-positive homes showed elevated antibody titres to legionella or the presence of legionella antigen in urine. For the immunocompetent hosts, the risk of contracting Legionnaires' disease from exposure to contaminated household water supplies in the Pittsburgh area appears to be low.

Treatment of cerebellar infarction by decompressive suboccipital craniectomy

BACKGROUND AND PURPOSE

We present an anecdotal series of 11 patients without past history of stroke with progressive neurological deterioration while on medical therapy for large cerebellar infarctions. Clinical signs of brain stem compression developed in these patients. Computerized tomography of the head confirmed mass effect from brain edema. It was the clinical judgment of the neurologists and neurosurgeons that each of these 11 patients would expire without surgical intervention.

METHODS

All 11 patients (seven men, four women; mean age, 54 years) were treated with suboccipital craniectomy for decompression and temporary ventriculostomy for cerebrospinal fluid pressure monitoring and drainage.

RESULTS

Seven patients demonstrated neurological improvement on the first postoperative day. Two patients returned to their previous jobs 3 months after surgery. The Barthel Index indicated that six individuals were functioning with minimal assistance within a follow-up period of 16-60 months. The remaining three were functionally dependent. No mortality was noted in this series.

CONCLUSIONS

These results suggest that decompressive suboccipital craniectomy may be an effective, lifesaving procedure for malignant cerebellar edema after a large infarction.

Treatment of symptomatic syringomyelia with ventriculoperitoneal shunt: report of a case

We report on a 43-year-old female who, for 27 years, had thoracic scoliosis with curve convexity to the left side. She complained of rapid progression of the central cord syndrome in the past two years. Magnetic resonance imaging (MRI) demonstrated a syringomyelia with a direct connection between the fourth ventricle and the syrinx. The patient underwent a ventriculoperitoneal shunt and showed rapid neurologic improvement. A follow-up MRI showed dramatic shrinkage of the syrinx.

Using proteases to avoid false identification of DNA-protein complexes in gel shift assays

Gel mobility shift assays using crude nuclear extracts may result in the formation of multiple DNA-protein complexes reflected by their discrete gel mobilities. Identification of the multiple complexes can sometimes be complicated by the presence of protease activities in the extract as demonstrated here. We describe a simple protease-mediated partial digestion method that can be coupled with the gel shift assay to overcome the problem. The combined approach enables us to identify gel complexes that arise from protein degradation and therefore is suitable for analyzing those DNA-binding proteins exhibiting prominent protease sensitivity. The method should prove particularly informative in the search for tissue-specific complexes when crude extracts from different sources are compared by the gel shift assay.

Differential detection of multiple DNA-binding complexes using dissimilar polyanion competitors

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Overexpression of RRE-derived sequences inhibits HIV-1 replication in CEM cells

Overexpression of sequences corresponding to the major Rev-binding site in the Rev response element of human immunodeficiency virus type 1 (HIV-1) (RRE decoys) was used to render cells resistant to HIV-1 replication. This was accomplished by the use of a chimeric tRNA-RRE transcription unit in a double-copy murine retroviral vector to express high levels of HIV-1 RRE-containing transcripts in CEM SS cells. Replication of HIV-1 was inhibited more than 90% in cells expressing chimeric tRNA-RRE transcripts, as determined by in situ immunofluorescence analysis and a p24 antigen ELISA test. Analysis of RNA from HIV-1-infected cells suggests that expression of RRE-containing sequences in CEM SS cells inhibits HIV-1 replication by interfering with Rev function, presumably by competing for Rev binding to its physiological target. The use of a subfragment of RRE as decoy RNA reduces the likelihood that essential cellular factors will be sequestered in cells expressing the decoy RNA. Thus, use of RRE-based decoy RNA to inhibit HIV-1 replication may represent a safer alternative to the use of TAR decoy RNA.

Activation of skeletal alpha-actin gene transcription: the cooperative formation of serum response factor-binding complexes over positive cis-acting promoter serum response elements displaces a negative-acting nuclear factor enriched in replicating myoblasts and nonmyogenic cells

Three upstream CBAR cis-acting promoter elements, containing the inner core CC(A/T)6GG of the serum response element (SRE), are required for myogenic cell type-restricted expression of the avian skeletal alpha-actin gene (K.L. Chow and R.J. Schwartz, Mol. Cell. Biol. 10:528-538, 1990). These actin SRE elements display differential binding properties with two distinct nuclear proteins, serum response factor (SRF) and another factor described here as F-ACT1. SRF is able to bind to all actin SREs with various affinities. This multisite interaction is marked by cooperative binding events in that the two high-affinity proximal and distal SREs facilitate the weak central-site interaction with SRF, leading to the formation of a higher-order SRF-promoter complex. Functional analyses reveal that undisrupted multiple SRF-DNA interactions are absolutely essential for promoter activity in myogenic cells. F-ACT1, present at higher levels in nonmyogenic cells and replicating myoblasts than in myotubes, binds solely to the proximal SRE, and its binding is mutually exclusive with that of SRF owing to their overlapping base contacts. The cooperative promoter binding by SRF, however, can effectively displace prebound F-ACT1. In addition, an intact F-ACT1 binding site acts as a negative promoter element by restricting developmentally timed expression in myoblasts. F-ACT1 may therefore act as a repressor of skeletal alpha-actin gene transcription. This interplay between F-ACT1 and SRF may constitute a developmental as well as a physiologically regulated mechanism which modulates sarcomeric actin gene expression.

Suppression of sodium arsenite-potentiated cytotoxicity of ultraviolet light by cycloheximide in Chinese hamster ovary cells

Post-treatment with sodium arsenite synergistically increased the cytotoxicity of ultraviolet (UV) light. The potentiation of UV cytotoxicity by sodium arsenite was apparently suppressed by cycloheximide (CHM), a protein synthesis inhibitor. The protective effect of CHM against sodium arsenite-potentiated UV cytotoxicity was well correlated to its activity in inhibiting the synthesis of stress proteins, particularly a small polypeptide with a molecular weight of 8500 dalton. This small stress protein was demonstrated as ubiquitin by immunoprecipitation. Our results also showed that neither ubiquitin induction nor potentiation of UV cytotoxicity by post-treatment with sodium arsenite was observed in the stationary cells. Thus, we suggested that ubiquitin is possibly involved in the action of arsenite in potentiating UV-induced cell killing.

Transforming growth factor beta 1, a potent chemoattractant for human neutrophils, bypasses classic signal-transduction pathways

Transforming growth factor beta 1 (TGF-beta 1), a homodimeric polypeptide (Mr 25,000), derives from inflammatory cells and acts as a chemoattractant for monocytes and fibroblasts. We report here that TGF-beta 1 is also the most potent chemoattractant yet described for human peripheral blood neutrophils. Recombinant TGF-beta 1 elicited dose-dependent directed migration of neutrophils under agarose that was inhibited in the presence of a neutralizing antibody to TGF-beta 1. Maximal chemotaxis was evoked by TGF-beta 1 at femtomolar concentrations, whereas conventional chemoattractants act at nanomolar concentrations: on a molar basis, TGF-beta 1 was 150,000 times more potent than fMet-Leu-Phe. In contrast, TGF-beta 1 provoked neither exocytosis nor the production of superoxide by neutrophils. We further analyzed the mechanism by which TGF-beta 1 elicits chemotaxis (GTPase activity, [Ca2+], and actin polymerization). In contrast to the conventional chemoattractant fMet-Leu-Phe, TGF-beta neither activated classic heterotrimeric guanine nucleotide-binding proteins nor provoked global mobilization of intracellular Ca2+. Chemoattraction by both fMet-Leu-Phe and TGF-beta 1 was inhibited by cycloheximide and actinomycin D. Moreover, chemotaxis in response to TGF-beta 1 was associated with the polymerization of actin. The selectivity and potency of TGF-beta 1 as a chemoattractant suggest that it elicits directed cell migration by means of a pathway that depends not on classic intracellular signals but on protein synthesis.

Acylation of alkyllysophospholipids by Fischer sarcoma microsomes

Acylation of alkyllysophospholipids in most cells occurs by: (a) CoA-independent transacylation, (b) CoA-dependent transacylation, and (c) acyl-CoA-dependent acylation. Using a recently developed high-performance liquid chromatography method, we have investigated the factors that influence the molecular species composition of the acylated products formed via these pathways with 1-hexadecyl-2-lyso-sn-glycero-3-phosphocholine (alkyllyso-GPC) or 1-hexadecyl-2-lyso-sn-glycero-3-phospho-ethanolamine (alkyllyso-GPE) as substrates for the enzymes in Fischer R-3259 sarcoma microsomes. We found that short incubation times and low substrate concentrations favored the formation of polyunsaturated molecular species, i.e., 16:0-22:6, 16:0-22:5 (n - 3), and 16:0-20:4. Also, in agreement with results from other systems, CoA-independent transacylation produced a high percentage of polyunsaturated molecular species; acyl-CoA-dependent acylations generated the least polyunsaturated molecular species and CoA-dependent transacylation gave intermediate values. Furthermore, no substrate selectivity occurred with respect to alkyl chain lengths of alkyllyso-GPE; similar molecular species composition was obtained with either hexadecyllyso-GPE or octadecyllyso-GPE as substrates. Responses to N-ethylmaleimide inhibition and heat inactivation as well as pH optima suggest the same enzyme catalyzes the CoA-independent transacylation of both alkyllyso-GPC and alkyllyso-GPE.

Mean flow velocity in the right common carotid artery before and after maximal exercise

The effect of exercise on mean flow velocity (MFV) in the right common carotid artery (RCC) was studied using pulsed Doppler ultrasound. MFV was measured at rest and at 2 minutes intervals after a 6 minute rowing ergometer test. Age-related maximum heart rate of 190 +/- 10 beats.min-1, maximum respiratory rate of 60 +/- 5 breaths.min-1, and postexercise lactate level of greater than 8 mmol.l-1 were the criteria used to define maximal exercise. The control group comprised 13 healthy, active males, mean age 19.8 years, with 19 healthy oarsmen, mean age 19.9 years, in the exercise group. At rest, MFV in the RCC was found to be 18.6 +/- 5.6 and 16.4 +/- 6.3 cm.min-1 in the control and exercise groups respectively. After exercise, MFV decreased to 21% of its resting value and remained significantly reduced (posthoc tests, Newman Keuls at alpha = 0.01) until 14-16 minutes of recovery. Mean systemic arterial pressure (MSAP) remained within normal limits. Mean age-related maximum heart rate was 182 +/- 3 beats.min-1, respiratory rate 58 +/- 3 breaths.min-1, and postexercise serum lactate 20.2 +/- 3.5 mmol.l-1 which satisfied the criteria for maximal exercise. In this group of young males, MFV in the RCC decreased markedly after maximal exercise and remained significantly reduced for a long period. This sustained reduction in MFV has not previously been described and is most likely due to vasoconstriction in distal cerebral resistance arterioles mediated by hypocapnia and autonomic activity.

Metabolism of platelet activating factor in lung

PAF is known to be produced by two independent enzymatic pathways. The remodeling route involves structural modification of a membrane phospholipid (1-alkyl-2-acyl-sn-glycero-3-phosphocholine) by substitution of an acetate for the acyl group at the sn-2 position. In contrast, the de novo pathway includes a sequence of acetylation, dephosphorylation, and phosphocholine addition, starting with the alkyl analog of lyso-phosphatidic acid. Hypersensitivity reactions with PAF as the autacoid are triggered by activation of the remodeling enzymes to produce excessive amounts of PAF. Inactivation of PAF occurs primarily by hydrolysis of the acetate group in a reaction catalyzed by acetylhydrolase. Results of our studies indicate that biosynthesis and catabolism of PAF by membrane preparations from both lung tissue and alveolar macrophages are qualitatively similar to that found in other cells. All of the enzymatic activities for both the remodeling and de novo pathways of PAF biosynthesis occur in the lung. Recent experiments indicate the initial reaction that produces lyso-PAF in the remodeling pathway of PAF biosynthesis is under the control of a CoA-independent transacylase that is capable of catalyzing both the hydrolysis of the acyl moiety of the alkylacylglycerophosphocholine precursor and its transfer to another lyso-phospholipid. The substrate specificity for the phospholipase A2 component of this reaction is for alkylacylglycerophosphocholines possessing arachidonate at the sn-2 position. Other polyunsaturated alkylacylglycerophosphocholines appear to be utilized as PAF precursors too, albeit to a lesser extent than the 20:4 species. The CoA-independent transacylase and its high affinity for the transfer of arachidonate to lyso-PAF appears to be a very prominent enzyme activity in rat lung membranes.

Point mutations in the turnip crinkle virus capsid protein affect the symptoms expressed by Nicotiana benthamiana

In an effort to determine the biological function(s) of the capsid protein protruding domains unique to the plant carmo- and tombusviruses, we constructed turnip crinkle virus (TCV) mutants in which tandem, in-frame translation terminators replaced the first two codons of the five-amino acid hinge between the shell and the protruding domains of the TCV capsid protein. One of the mutants replicated in inoculated leaves and protoplasts without detectable accumulation of capsid protein. The mutant lacked the capacity to move systemically in Brassica campestris and Nicotiana benthamiana. After 8 weeks, revertant virions that had regained the capacity to move systemically were purified and found to have sense codons at the positions of the introduced translation terminators. One of the revertants, with amino acid substitutions in the hinge, elicited milder symptoms than those elicited by the wild-type virus, and another elicited more severe symptoms. Oligonucleotide-directed mutagenesis was used to show that the hinge mutations were sufficient to elicit the milder, but not the more severe, symptom syndrome. Single amino acid substitutions were also shown to be sufficient to elicit the milder, but not the more severe, symptoms.

A coenzyme A-independent transacylase is linked to the formation of platelet-activating factor (PAF) by generating the lyso-PAF intermediate in the remodeling pathway

The remodeling pathway for the biosynthesis of platelet-activating factor (PAF) consists of the following reaction sequence: alkylacylglycerophosphocholine----lyso-PAF----PAF. Results presented in this article describe a novel transacylase activity that generates the lyso-PAF intermediate, which can then be acetylated to form PAF. Ethanolamine-containing lysoplasmalogens, 1-acyl-2-lyso-sn-glycero-3-phosphoethanolamine, alkyllysophosphoethanolamine, unlabeled lyso-PAF, 1-acyl-2-lyso-GPC, where GPC is sn-glycero-3-phosphocholine, and choline-containing lysoplasmalogens were all able to stimulate the formation of [3H]lyso-PAF from a [3H]alkylacyl-GPC precursor pool associated with HL-60 cell (granulocytic type) membranes. Other glycerolipids containing free hydroxyl groups (3-alkyl-2-lyso-sn-glycero-1-phosphocholine, lysophosphatidylserine, lysophosphatidylinositol, diacylglycerols, alkylglycerols, and monoacylglycerols), cholesterol, phosphatidylcholine, and phosphatidylethanolamine had no stimulatory effect on the release of [3H]lyso-PAF from the prelabeled membranes under identical incubation conditions. The observed transacylase reaction is directly coupled to PAF production, since the addition of a lysoethanolamine plasmalogen preparation to HL-60 membranes in the presence of [14C]acetyl-CoA stimulated PAF formation; under these conditions the lysoethanolamine plasmalogen was acylated. The transacylase responsible for the release of lyso-PAF from the membrane-associated alkylacyl-GPC was not affected by Ca2+, EGTA, or a known phospholipase A2 inhibitor, p-bromophenacyl bromide. The fact that the unnatural analog of lyso-PAF, lysophosphatidylserine, and lysophosphatidylinositol did not influence transacylase activity, whereas detergents such as deoxycholate and Triton X-100 inhibited the activity, demonstrated the observed stimulatory effects of the choline- and ethanolamine-containing lysophospholipids on the formation of [3H]lyso-PAF from [3H]alkylacyl-GPC were not due to any detergent property of these lysophospholipids. Thus, we conclude a CoA-independent transacylase (possessing phospholipase A2/acyltransferase activities) can be responsible for the formation of the lyso-PAF intermediate in the remodeling route of PAF biosynthesis.

Biosynthesis of choline plasmalogens in neonatal rat myocytes

The alk-1-enyl bond in plasmenylethanolamine is formed from plasmanylethanolamine by the action of a microsomal cytochrome b5-dependent desaturase. However, the origin of the alk-1-enyl linkage in plasmenylcholine, a significant subclass of phospholipids in heart tissues of certain animal species, is not yet known. We have used neonatal rat myocytes as a model to study the biosynthesis of plasmenylcholine in the present studies since they have a phospholipid composition and subclasses of 1,2-diradyl-sn-glycero-3-phosphocholine (-GPC) similar to those of neonatal rat hearts. When equal concentrations of [3H]hexadecyllyso-GPC or [3H]hexadecyllyso-sn-glycero-3-phosphoethanolamine (-GPE) are incubated under identical conditions with myocytes for 4, 12, and 24 h, the rate of plasmenylcholine formation is faster from [3H]hexadecyllyso-GPE than from [3H]hexadecyllyso-GPC. Also, when [3H]alkyllyso-GPC and alkyllyso-[N-methyl-14C]GPC are incubated with rat myocytes for various times up to 24 h, the 3H/14C ratio in the diacyl-GPC plus alkylacyl-GPC fraction and alkyllyso-GPC remains relatively constant (3H/14C = 2.7), whereas the 3H/14C of plasmenylcholine increases from 0.3 at 2 h to 1.7 after 24 h. Finally, when the rat myocytes are prelabeled with [3H]alkyllyso-GPE for 4 h and then reincubated with either [14C]choline or [14C]methionine for 1 or 3 h, both [14C]choline and [14C]methionine are incorporated into plasmenylcholine, except the 14C/3H is much higher (5- to 15-fold) in the [14C]choline-labeled plasmenylcholine than in the [14C]methionine-labeled plasmenylcholine. Collectively, our data show plasmenylcholine is not directly derived from plasmanylcholine or lysoplasmanylcholine, but instead is formed from plasmenylethanolamine via some type of hydrolytic exchange mechanism, and the contribution of plasmenylethanolamine through methylation to the synthesis of plasmenylcholine is of limited capacity.

Occurrence of ether-containing inositol phospholipids in bovine erythrocytes

Several proteins including bovine erythrocyte acetylcholinesterase are anchored in the membrane through glycoinositol phospholipids containing an alkyl linkage at the sn-1 position of the glycerol. However, the existence of 1-alkyl-2-acyl-sn-glycero-3-phosphoinositol (alkylacyl-GPI) in biological systems has not been demonstrated. In this study, we identified the presence of alkylacyl-GPI in bovine erythrocytes by the following criteria: (1) TLC-Rf value, (2) radyllyso-GPI was produced after phospholipase A2 treatment of the diradyl-GPI, and (3) benzoate derivatives of alkylacylglycerols produced by phospholipase C hydrolysis of diradyl-GPI had the same retention time as that of authentic alkylacylglycerobenzoates on normal-phase HPLC. Diradyl-GPI consisted of 5-10% alkylacyl-GPI. Reverse-phase HPLC analysis of alkylacylglycerobenzoates derived from bovine erythrocyte alkylacyl-GPI showed a multiplicity of species with 18:0-20:4 (11.7%), 16:0-18:1 + 18:0-18:2 (34.9%), and 18:0-18:1 (19.4%) being the major components. Composition of alkyl chains of alkylacyl-GPI from bovine erythrocytes was similar to the reported value for alkylacylglycerols isolated from the glycoinositol phospholipid anchor of bovine erythrocyte acetylcholinesterase. Based on these results, we suggest that alkylacyl-GPI serves as a precursor for the glycoinositol phospholipid of the anchored proteins.

Sodium arsenite induces ATP depletion and mitochondrial damage in HeLa cells

Our present results show that treatment with sodium arsenite apparently decreases cellular ATP levels in a dose- and time-dependent manner in HeLa S-3 cells. The reduction in ATP induced by sodium arsenite was possibly through mitochondrial damage, since treatment with sodium arsenite resulted in reduction of rhodamine 123 accumulation and disruption of the structure of the cristae in mitochondria. However, all of these changes could be reversed by removing sodium arsenite from the culture medium. The levels of ATP depletion were correlated with the killing effects of sodium arsenite in HeLa S-3 cells.

Expression of chimeric tRNA-driven antisense transcripts renders NIH 3T3 cells highly resistant to Moloney murine leukemia virus replication

NIH 3T3 cells infected with Moloney murine leukemia virus (MoMLV) express high levels of virus-specific RNA. To inhibit replication of the virus, we stably introduced chimeric tRNA genes encoding antisense templates into NIH 3T3 cells via a retroviral vector. Efficient expression of hybrid tRNA-MoMLV antisense transcripts and inhibition of MoMLV replication were dependent on the use of a particular type of retroviral vector, the double-copy vector, in which the chimeric tRNA gene was inserted in the 3' long terminal repeat. MoMLV replication was inhibited up to 97% in cells expressing antisense RNA corresponding to the gag gene and less than twofold in cells expressing antisense RNA corresponding to the pol gene. RNA and protein analyses suggest that inhibition was exerted at the level of translation. These results suggest that RNA polymerase III-based antisense inhibition systems can be used to inhibit highly expressed viral genes and render cells resistant to viral replication via intracellular immunization strategies.

Skeletal effects of sodium fluoride during hypokinesia

This study tested the capacity of fluoride (F) to prevent the disuse-associated reduction in bone formation/growth. Suspending young male Wistar rats by the tail for 2-2.5 weeks reduced femoral cortical (P less than 0.05) and trabecular (P less than 0.01) bone areas. Tetracycline labelling showed that the decrement in cortical area was largely due to a reduction in the percent periosteal mineralizing surface (PsMS). Periosteal mineral apposition rate (PsMAR) was not affected. Endosteal mineralizing surface (EsMS) and mineral apposition rate (EsMAR) were significantly stimulated spontaneously during the second week of suspension. F treatment (5 mg/kg/day i.p.) prevented the loss in bone area, and established a trend toward increased PsMS without affecting EsMS and EsMAR. None of these changes are associated with alterations in serum Ca, P or osteocalcin. F treatment in hypokinetic animals caused a decrease in serum PTH (-21% compared to control; P = 0.001). We conclude that F prevents the development of hypokinetic osteopenia in rats.

Effects of mithramycin, mitomycin, daunorubicin, and bleomycin on human subconjunctival fibroblast attachment and proliferation

Scar formation and fibrosis are the most common causes of ultimate glaucoma filtration surgery failure. The authors used Coulter counter, hexosaminidase, and 3H-thymidine assays to evaluate the effects of mithramycin, mitomycin, daunorubicin, and bleomycin on human subconjunctival fibroblast growth in tissue culture. Fifty percent inhibitory doses (ID50) for each drug on different days of incubation with fibroblasts were calculated with these three assays. Among these four drugs only daunorubicin exerted a significant effect on cellular attachment, showing cytotoxicity at 4 x 10(-6) M. However, all drugs had antiproliferative effects. Daunorubicin was the most potent drug in the concentration range studied. Mithramycin had a narrow therapeutic range in tissue culture. Cellular antiproliferative responses to mitomycin and bleomycin were more gradual. These drugs have potential applications in the prevention of glaucoma filtration surgery failure.

Emergency percutaneous transluminal coronary angioplasty for acute myocardial infarction in patients 70 years of age and older

Direct percutaneous transluminal coronary angioplasty (PTCA) was performed as the primary means of establishing reperfusion during acute myocardial infarction in 105 elderly patients (mean age +/- standard deviation 75 +/- 4 years) at a mean of 5.5 +/- 4.0 hours from symptom onset. Fifty-two patients (50%) had anterior infarctions, 70 (67%) had significant narrowing in greater than 1 vessel, and 12 (11%) were in cardiogenic shock. Primary success was achieved in 91% of the infarct-related arteries. Four patients with failed PTCA underwent emergency bypass surgery; 10 had early symptomatic reocclusion of the dilated vessel. There was 1 death acutely in the catheterization laboratory. The overall in-hospital mortality was 18%. Three-vessel coronary artery disease and cardiogenic shock on presentation were the strongest predictors of in-hospital death. Global ejection fraction improved from 54 +/- 13 to 61 +/- 15% (p less than 0.001). The 1- and 5-year survival rates, including in-hospital deaths, were 73 and 67%, respectively. It is concluded that direct PTCA is an effective means of salvaging ischemic myocardium during acute myocardial infarction in the elderly patient. It is associated with a high success rate and low complication rate. The short- and long-term survival in this high-risk group of patients are improved compared with survival rates in historical controls.

Primary hyperparathyroidism in patients with renal stones

There has been an observed decline in the incidence of renal stones in patients with primary hyperparathyroidism. Some believe that this is related to earlier surgical intervention. Two studies from the 1950s examined the reverse questions to determine the prevalence of primary hyperparathyroidism in patients with renal stones. This report examined 1,500 consecutive patients treated by lithotripsy seen at the Georgetown University Medical Center and found, using the historical criterion for diagnosis of hyperparathyroidism (a serum calcium level of 10.5 milligrams per deciliter or greater) that the prevalence had decreased significantly from 8.0 per cent to our level of 3.02 per cent. Neither age nor sex contributed significantly to this decrease, and there were significantly more calcium stones than in the previous studies. Using an elevated calcium level with an elevated chloride to phosphate ratio as criteria for a diagnosis of probable primary hyperparathyroidism, a true prevalence of 1.65 per cent (+/- 0.6 per cent) was found. We believe that there has been a significant decrease in the frequency of primary hyperparathyroidism in the general population of patients with renal stones.

Successful replantation of nose by microsurgical technique, and review of literature

We present a case of total amputation of a major portion of the nose of a 10-year-old boy, which was successfully replanted by microsurgical technique. A 489-year review of the literature revealed the rarity of successful nasal replacement following amputation.