Polyarthralgia-arthritis syndrome induced by low doses of rifabutin

We describe 2 cases of polyarthralgia-arthritis syndrome induced by rifabutin, an effective treatment for infections of Mycobacterium avium intracellulare complex. This syndrome has been reported with doses higher than 1 g per day when rifabutin is given in monotherapy. But our cases were treated with low doses, 300-450 mg per day, in combination with clarithromycin. The plasma concentration of rifabutin has been shown to be increased by clarithromycin, suggesting that co-prescription of clarithromycin could lead to development of rifabutin induced polyarthralgia-arthritis syndrome.

Recombinant interleukin 2 adjunctive therapy in multidrug-resistant tuberculosis

Multidrug-resistant tuberculosis patients respond poorly to antituberculosis therapy and therefore require new modalities of treatment to overcome the infection. Administration of low dose recombinant human interleukin 2 (rhuIL-2) in combination with chemotherapy to multidrug-resistant tuberculosis patients resulted in reduced or cleared sputum acid-fast bacilli in about 60% of the patients in association with enhanced activation of the immune system. Daily rhuIL-2 administration for 30 days induced increases in CD25+ and CD56+ cells in the blood. rhuIL-2 therapy also resulted in increased expression of gamma-interferon and IL-2 mRNA at the site of a delayed-type hypersensitivity (DTH) response to purified protein derivative of tuberculin. Differential display reverse transcriptase PCR revealed several genes expressed at the DTH skin test site that were up- or down-regulated during rhuIL-2 treatment. The differentially regulated genes included components of endocytic vacuoles, enzymes of the respiratory pathway and other regulators of cellular function. The physiological importance of the differential expression of these genes is under investigation to determine their roles in leukocyte activation and in the development of an antimycobacterial response.

Geographic heterogeneity of 4 common worldwide cystic fibrosis non-DF508 mutations in Brazil

Cystic fibrosis (CF) is an autosomal recessive disease caused by at least 750 different mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The frequency of the most common mutation (DF508) in Brazilian patients of European origin is 47%. To determine the frequency of 4 other common CF mutations (G542X, G551D, R553X, and N1303K) in Brazilian patients of European origin, we used direct polymerase chain reaction (PCR) amplification of DNA obtained from dried blood spots on Guthrie cards. The DNA came from 247 non-DF508 chromosomes from 172 Brazilian CF patients ascertained from 5 different states of Brazil. The results show that the 4 mutations account for 17% of the non-DF508 alleles and only 9% of the total number of Brazilian CF alleles. Overall, the frequency of each mutation is different from northern European and North American populations but similar to southern European populations, mainly the Italian and Spanish populations. When Brazilian patients of European origin are grouped according to state of birth, the frequencies of the mutations are significantly different between southern and southeastern states of Brazil. Therefore there are serious implication for risk assessment of DNA-based tests in heterogeneous populations such as Brazilians. Further studies are needed to identify the remaining 44% of CF mutations for the different populations and regions of Brazil.

Fetal yawning activity in normal and high-risk fetuses: a preliminary observation

OBJECTIVE

To study yawning activity in healthy fetuses and in fetuses at high risk.

METHODS

Yawning activity was studied in 16 healthy and 22 high-risk fetuses. Studies were performed in the postprandial state at 09.00 and 12.00 in a quiet room with the woman in the lateral recumbent position. All ultrasound examinations were performed using a 3.5-MHz Acuson 128 PX curvilinear probe. Fetal lips, mouth, tongue, pharynx, larynx, trachea and esophagus were surveyed in serial coronal and sagittal planes. All fetal mouthing movements were analyzed by a review of the videotape in slow motion.

RESULTS

In both normal and high-risk fetuses, yawning was represented by isolated mouthing movements and consisted of slow opening of the mouth with simultaneous downward movements of the tongue. This phase occupied 50-75% of the yawning cycle. After reaching its maximum opening, the mouth remained wide open for 2-8 s and returned to its resting position within seconds. Growth-restricted fetuses demonstrated yawning patterns consisting of isolated yawns similar to those seen in healthy fetuses. Unusual bursts of fetal yawning activity were recorded in anemic fetuses.

CONCLUSION

Yawning activity in anemic fetuses may represent a compensatory process to increase venous return to the heart.

Mycobacterium tuberculosis catalase and peroxidase activities and resistance to oxidative killing in human monocytes in vitro

Mycobacterium tuberculosis has a relatively high resistance to killing by hydrogen peroxide and organic peroxides. Resistance may be mediated by mycobacterial catalase-peroxidase (KatG) and possibly by alkyl hydroperoxide reductase (AhpC). To determine the interrelationship between sensitivity to H2O2, catalase and peroxidase activities, and bacillary growth rates measured both intracellularly in human monocytes and in culture medium, we examined one laboratory strain, two clinical isolates, and three recombinant strains of M. tuberculosis with differing levels of KatG and AhpC. Five of the mycobacterial strains had intracellular doubling times of 27 to 32 h, while one KatG-deficient clinical isolate (ATCC 35825) doubled in approximately 76 h. Killing of mycobacteria by exogenously added H2O2 was more pronounced for intracellular bacilli than for those bacilli derived from disrupted monocytes. Strains with no detectable KatG expression or catalase activity were relatively sensitive to killing (43 to 67% killing) by exogenous H2O2. However, once even minimal catalase activity was present, mycobacterial catalase activity over a 10-fold range (0.56 to 6.2 U/mg) was associated with survival of 85% of the bacilli. Peroxidase activity levels correlated significantly with resistance of the mycobacterial strains to H2O2-mediated killing. An endogenous oxidative burst induction by 4beta-phorbol 12beta-myristate 13alpha-acetate treatment of infected monocytes reduced the viability of the KatG null strain (H37Rv Inhr) but not the KatG-overexpressing strain [H37Rv(pMH59)]. These results suggest that mycobacterial resistance to oxidative metabolites (including H2O2 and other peroxides) may be an important mechanism of bacillary survival within the host phagocyte.

HHV8 status in Kaposi's sarcoma associated with multiple myeloma

Kaposi's sarcoma in its sporadic or HIV-related form is due to a gamma herpesvirus, the human herpes virus 8 (HHV8). No data have been published on the potential role of the HHV8 in Kaposi's sarcoma occurring in multiple myeloma patients. A case is reported of a patient in whom four serum samples taken between the diagnosis of multiple myeloma and the occurrence of a Kaposi's sarcoma one year later tested positive for antibody to the HHV8. Similar findings have been reported in patients with other types of Kaposi's sarcoma. PCR studies for HHV8 DNA were positive on a Kaposi's sarcoma biopsy but negative on a bone biopsy, militating against a role for the HHV8 in the genesis of multiple myeloma.

Dose response of various radiation detectors to synchrotron radiation

Accurate dosimetry is particularly difficult for low- to medium-energy x-rays as various interaction processes with different dependences on material properties determine the dose distribution in tissue and radiation detectors. Monoenergetic x-rays from synchrotron radiation offer the unique opportunity to study the dose response variation with photon energy of radiation detectors without the compounding effect of the spectral distribution of x-rays from conventional sources. The variation of dose response with photon energies between 10 and 99.6 keV was studied for two TLD materials (LiF:Mg,Ti and LiF:Mg,Cu,P), MOSFET semiconductors, radiographic and radiochromic film. The dose response at synchrotron radiation energies was compared with the one for several superficial/orthovoltage radiation qualities (HVL 1.4 mm Al to 4 mm Cu) and megavoltage photons from a medical linear accelerator. A calibrated parallel plate ionization chamber was taken as the reference dosimeter. The variation of response with x-ray energy was modelled using a two-component model that allows determination of the energy for maximum response as well as its magnitude. MOSFET detectors and the radiographic film were found to overrespond to low-energy x-rays by up to a factor of 7 and 12 respectively, while the radiochromic film underestimated the dose by approximately a factor of 2 at 24 keV. The TLDs showed a slight overresponse with LiF:Mg, Cu, P demonstrating better tissue equivalence than LiF:Mg, Ti (maximum deviation from water less than 25%). The results of the present study demonstrate the usefulness of monoenergetic photons for the study of the energy response of radiation detectors. The variations in energy response observed for the MOSFET detectors and GAF chromic film emphasize the need for a correction for individual dosimeters if accurate dosimetry of low- to medium-energy x-rays is attempted.

Surgical considerations in the contemporary management of biliary tract disease in the postpartum period

BACKGROUND

Excluding sterilization procedures, no experience with laparoscopic procedures in the postpartum period has been reported. The postpartum patient may have unique characteristics that must be recognized for safe management.

METHODS

The authors prospectively studied 1,100 consecutive biliary patients in a private surgical practice since the introduction of laparoscopic cholecystectomy (LC). The group includes 34 patients who presented with biliary tract disease and were operated upon within 6 weeks of obstetrical delivery. Laparoscopic procedures were performed on these 34 patients 1 to 42 days following vaginal (26) or Cesarean (8) deliveries.

RESULTS

All patients had calculous cholecystitis. Choledocholithiasis was documented in 10 (29%) patients, including 3 patients (9%) with missed common duct stones, and strongly suggested in 5 (15%) others. Open biliary procedures were required for 2 patients. One patient returned to surgery for an ERCP-related complication. Follow up is known for all patients. There were no delayed complications.

CONCLUSIONS

The laparoscopic approach to biliary tract disease in the postpartum period is safe. Recent vertical Cesarean incisions can withstand the strain of a reduced pneumoperitoneum. The high incidence of choledocholithiasis calls for routine cholangiography in the postpartum patient.

rhuIL-2 adjunctive therapy in multidrug resistant tuberculosis: a comparison of two treatment regimens and placebo

SETTING

Low-dose recombinant human interleukin 2 (rhuIL-2) adjunctive immunotherapy in multidrug resistant tuberculosis (MDR-TB) patients.

OBJECTIVE

Evaluation of the effects of daily versus pulse-administered rhuIL-2 compared to placebo.

DESIGN

MDR-TB patients on best available antituberculous chemotherapy received rhuIL-2 for 30 consecutive days (daily therapy), or for 5 days followed by a 9-day 'rest', for three cycles (pulse therapy). Placebo control patients received diluent. The cumulative total dose of rhuIL-2 given to each patient in either rhuIL-2 treatment group was the same. Patient immunologic, microbiologic, and radiologic responses were compared.

RESULTS

The three treatment schedules induced different results. Immune activation was documented in patients receiving daily rhuIL-2 therapy. Numbers of CD25+ and CD56+ cells in the peripheral blood were increased in these patients, but not in patients receiving pulse rhuIL-2 or placebo. In addition, 5/8 (62%) patients receiving daily rhuIL-2 demonstrated reduced or cleared sputum bacterial load while only 2/7 (28%) pulse rhuIL-2 treated and 2/8 (25%) controls showed bacillary clearance. Chest radiographs of 7/12 (58%) patients receiving daily rhuIL-2 indicated significant improvement over 6 weeks. Only 2/9 (22%) pulse rhuIL-2-treated patients and 5/12(42%) placebo controls showed radiologic improvement.

CONCLUSION

Daily low dose rhuIL-2 adjunctive treatment stimulates immune activation and may enhance the antimicrobial response in MDR-TB.

Selective increase in plasma tumor necrosis factor-alpha and concomitant clinical deterioration after initiating therapy in patients with severe tuberculosis

The initiation of antituberculosis treatment in patients with severe tuberculosis may be accompanied by clinical deterioration and even death before any improvement occurs. To investigate this phenomenon, newly diagnosed human immunodeficiency virus-negative adults with severe tuberculosis were followed for the first 42 days of standard short-course therapy. Clinical status, serum lactate, plasma cytokine, and plasma cytokine receptor levels were monitored on days 0, 3, and 7 and then weekly for up to 42 days. Following 7 days of antituberculosis therapy, a significant transient decrease in mean Karnofsky score (P < .001), a concomitant increase in serum lactate (P = .06), a decrease in patient weight (P = .02), and an increase in plasma tumor necrosis factor-alpha (TNF-alpha) concentrations (P = .04) were observed. Plasma levels of soluble interleukin-2 receptor, interferon-gamma, interleukin-6, and TNF-alpha receptor decreased over the 42-day study period. These observations suggest that increases in plasma TNF-alpha levels may be associated with clinical deterioration observed early in the treatment of severe tuberculosis.

Effect of cytokine modulation by thalidomide on the granulomatous response in murine tuberculosis

SETTING

Experimental murine tuberculosis.

OBJECTIVE

To evaluate the effect of cytokine modulation by thalidomide on the progression of the lung granulomatous response following aerosol tuberculosis infection in mice.

DESIGN

Mice infected by the respiratory route with 200-500 viable Mycobacterium tuberculosis Erdman were treated with daily subcutaneous injections of thalidomide (30 mg/kg) or saline for 4 weeks. The bacillary load, granulomatous response and cytokine production in the lungs were evaluated.

RESULTS

Aerosol M. tuberculosis infection resulted in a progressive granulomatous response in the lungs. At 28 days after infection, large granulomata with central necrosis and no apoptosis were observed. The infection induced high serum and lung cytokine mRNA levels. Thalidomide treatment resulted in a significant reduction in tumor necrosis factor-alpha, interleukin 6 (IL-6) and IL-10 protein levels (blood) and mRNA expression (lungs). IL-12 and interferon-gamma were unaffected. The lungs of thalidomide-treated mice had smaller granulomata with apoptotic cells and no necrosis. Thalidomide treatment did not change the bacillary load.

CONCLUSION

Thalidomide immunomodulation reduces inflammatory cytokines and concomitant lung pathology following acute aerosol M. tuberculosis infection, without increasing the bacillary load.

Multiple stress fractures in a scleroderma patient on methotrexate therapy

A patient on methotrexate therapy for scleroderma developed four stress fractures within a period of 13 months. She was not on steroid therapy and had no risk factors for osteoporosis. A review of the literature found 13 cases of stress fractures under methotrexate therapy. Whether methotrexate can induce bone changes remains controversial.

A combination of thalidomide plus antibiotics protects rabbits from mycobacterial meningitis-associated death

Tuberculous meningitis (TBM) is a devastating form of tuberculosis that occurs predominantly in children and in immunocompromised adults. To study the pathogenesis of TBM, a rabbit model of acute mycobacterial central nervous system infection was set up (8-day study). Inoculation of live Mycobacterium bovis Ravenel intracisternally induced leukocytosis (predominantly mononuclear cells), high protein levels, and release of tumor necrosis factor-alpha (TNF-alpha) into the cerebrospinal fluid within 1 day. Histologically, severe meningitis with thickening of the leptomeninges, prominent vasculitis, and encephalitis was apparent, and mortality was 75% by day 8. In animals treated with antituberculous antibiotics only, the inflammation and lesions of the brain persisted despite a decrease in mycobacteria; 50% of the rabbits died. When thalidomide treatment was combined with antibiotics, there was a marked reduction in TNF-alpha levels, leukocytosis, and brain pathology. With this combination treatment, 100% of the infected rabbits survived, suggesting a potential clinical use for thalidomide in TBM.

Thalidomide costimulates primary human T lymphocytes, preferentially inducing proliferation, cytokine production, and cytotoxic responses in the CD8+ subset

The efficacy of thalidomide (alpha-phthalimido-glutarimide) therapy in leprosy patients with erythema nodosum leprosum is thought to be due to inhibition of tumor necrosis factor alpha. In other diseases reported to respond to thalidomide, the mechanism of action of the drug is unclear. We show that thalidomide is a potent costimulator of primary human T cells in vitro, synergizing with stimulation via the T cell receptor complex to increase interleukin 2-mediated T cell proliferation and interferon gamma production. The costimulatory effect is greater on the CD8+ than the CD4+ T cell subset. The drug also increases the primary CD8+ cytotoxic T cell response induced by allogeneic dendritic cells in the absence of CD4+ T cells. Therefore, human T cell costimulation can be achieved pharmacologically with thalidomide, and preferentially in the CD8+ T cell subset.

Differential gene expression in response to adjunctive recombinant human interleukin-2 immunotherapy in multidrug-resistant tuberculosis patients

Administration of low-dose recombinant human interleukin 2 (rhuIL-2) in combination with multidrug chemotherapy to patients with multidrug-resistant tuberculosis (MDR TB) induces measurable changes in in vitro immune response parameters which are associated with changes in the clinical and bacteriologic status of the patients. To determine the molecular basis of these changes, we have used semiquantitative reverse transcriptase-initiated PCR (RT-PCR) and differential display technology. During rhuIL-2 treatment of MDR TB patients, decreased levels of gamma interferon (IFN-gamma) mRNA in peripheral blood mononuclear cells (PBMC) relative to baseline levels were observed. However, at the site of a delayed-type hypersensitivity (DTH) response to purified protein derivative of tuberculin (PPD), the expression of cellular IFN-gamma and IL-2 mRNAs was increased during rhuIL-2 therapy. Levels of other cytokine mRNAs were not significantly affected by rhuIL-2 administration. Using differential-display RT-PCR, we identified several genes expressed at the DTH skin test site which were up- or down-regulated during rhuIL-2 treatment. Cytochrome oxidase type I mRNA was increased in response to rhuIL-2 therapy relative to baseline levels, as was heterogeneous nuclear ribonuclear protein G mRNA. CD63, clathrin heavy chain, and beta-adaptin mRNAs, all of which encode proteins associated with the endocytic vacuolar pathway of cells, were also differentially regulated by rhuIL-2 administration. The differential effects of IL-2 were confirmed in vitro by using PBMC obtained from PPD-positive individuals stimulated with Mycobacterium tuberculosis and IL-2. The differential expression of genes may provide a surrogate marker for leukocyte activation at a mycobacterial antigen-specific response site and for the development of an enhanced antimicrobial response which may result in improved outcomes in MDR TB patients.

Degradation of hammerhead ribozymes by human ribonucleases

Hammerhead ribozymes were used as substrates to examine endoribonucleolytic activities in cell extracts and cultured human cells. Primer-extension analyses showed that ribozymes directed against tumor necrosis factor-alpha mRNA and human immunodeficiency virus type 1 tat mRNA were cleaved at UA and CA dinucleotides by extracts. Preferred cleavage sites were similar to those observed following digestion with RNase A, and cleavage was blocked by RNasin, an inhibitor of pyrimidine-specific ribonucleases. Removal of UA and CA dinucleotides rendered ribozymes more stable when incubated in cell extracts that were not significantly contaminated by extracellular nucleases. Placement of UA dinucleotides adjacent to a ribozyme in mRNA led to excision of the ribozyme from long transcripts during incubation in extracts. UA dinucleotides also made mRNA more labile than a control RNA when expressed from an endogenous plasmid gene in the human myeloid cell line U937. Similarly, UA and CA dinucleotides caused ribozymes to have a shorter half-life when delivered to U937 cells by lipofectin-mediated transformation. Taken together, these data indicate that one or more members of the pyrimidine-specific ribonuclease family is involved in the intracellular degradation of RNA, and they explain the paucity of UA dinucleotides in eukaryotic mRNA. Judicious manipulation of preferred target sequences of pyrimidine-specific ribonucleases may be useful in designing effective hammerhead ribozymes.

[Drowning in Israel--1990-1992]

There are no epidemiological studies of drowning in Israel in the scientific literature, despite prominent reports in the media. We analyzed the extent of mortality from drowning in Israel during 1990-92, attempting to identify and characterize groups at high risk, and to determine trends and differences between Israel and other countries. Computerized death certificate files were provided by the Israel government Central Bureau of Statistics; deaths from drowning were included among external causes codes E-830, 832, E-910, E-954, E-964, E-984. In Israel, as in the United States, mortality from drowning is the fourth cause of death among all unintentional causes, and the second cause in age-groups 1-24, ranking after transport accidents. During 1990-92 there were 1.2 drownings a year/100,000 population. The highest rates were found among young non-Jews 15-24 years old (7.8/100,000) and among elderly Jews (3.5/100,000). Unintentional drowning accounted for 89% of all deaths; while about 10% were defined as suicides. Males had a rate almost 3 times greater than females, and the among Arabs was 2.4 times greater than among Jews. The 1990-92 drowning rate was slightly lower than in previous years. Drowning rates in Israel are lower than in the United States, except in the elderly. Apparently the principal reason for this difference is difference in sites of drowning. In Israel most drownings occur in the sea, so site data are unavailable for international comparisons. Careful consideration of the categories (E-codes) included in the rates, and of local registration procedures, is necessary for international comparisons. Foreign workers, tourists and other nonresidents are not included in national vital statistics. But estimations based on Ministry of Interior sources show that foreign workers (most, recent arrivals) during the last few years are an extremely high risk group. Population-based drowning rates are not an accurate estimation of drowning risk, since universal exposure to the "opportunity to drown" is assumed.

High anti-cytomegalovirus (CMV) IgG antibody titer is associated with coronary artery disease and may predict post-coronary balloon angioplasty restenosis

Recent studies have demonstrated that cytomegalovirus (CMV) DNA was found in atherosclerotic coronary arteries in restenotic lesions, and prior infection with CMV could be a strong independent risk factor for restenosis after coronary atherectomy. We studied the correlation between anti-CMV antibody titer and coronary artery disease. Sixty-five patients (50 men and 15 women) with coronary artery disease were enrolled prospectively. All had symptomatic coronary artery disease with an angiographic documentation of a de novo single coronary lesion. All underwent balloon coronary angioplasty and were followed for 12 months with a thallium perfusion scan 3 months after angioplasty. Patients who had recurrent chest pain and/or a positive thallium scan had another coronary angiography. Blood samples were taken before angiography and 1 and 3 months later. Patients with high anti-CMV titer > or = 1:800 had a higher prevalence of coronary artery disease (p <0.001) than seropositive patients with a lower antibody titer (< or = 1:400); patients with high antibody titer (> or = 1:800) had a higher restenosis rate than seropositive patients with a low antibody titer (< or = 1:400) (p <0.05). High antibody titers against CMV (IgG) may be a strong marker for coronary artery disease, and might predict post-coronary angioplasty restenosis. These findings support the infectious theory of atherosclerosis (especially with prior CMV infection), and also suggest that a chronic immunologic response has a role in atherosclerosis and restenosis.

The distinctive features of influenza virus infection of dendritic cells

CD8+ cytolytic T lymphocytes (CTLs) are considered to be critical mediators for resistance to influenza virus infection. We have previously demonstrated that dendritic cells are potent antigen presenting cells in the development of anti-influenza CTLs. Here we identify distinctive features of the interaction of influenza virus with dendritic cells. Exposure of dendritic cells to influenza virus at MOIs of 2-4:1 leads to > 90% infection, as manifested by the expression of the viral proteins HA and NS1. The infection is non-toxic as viral protein expression is sustained for > 2 days with retention of viability, but little infectious virus is produced. Substantial induction of the anti-viral cytokine IFN-alpha also occurs. Influenza infection of macrophages also results in viral protein expression in a majority of cells, and synthesis of IFN-alpha. In contrast to dendritic cells, macrophages display evidence of apoptosis within 10-12 hours, and the majority of cells die within 24-36 hours. During this interval macrophages synthesize > 10-fold higher levels of virus than dendritic cells. Infected dendritic cells but not macrophages, can induce substantial CTL responses from purified blood CD8+ T cells in the absence of exogenous cytokines such as IL-2. Low levels of infection (MOIs of 0.02) are sufficient to generate potent CTL responses. Influenza virus expressing non-cleaved HA does not elicit CTLs indicating that virus must access the cytoplasm of dendritic cells to utilize traditional class I processing pathways. These observations indicate that DCs are distinct in their handling of influenza virus and for the induction of anti-viral immunity.

Autoimmune and inflammatory responses may have an additive effect in postpercutaneous transluminal coronary angioplasty restenosis

Patients who had an increase in their serum amyloid type A level of > 100% in the first 24 hours after percutaneous transluminal coronary angioplasty (PTCA) and also developed a positive antibody result (antinuclear factor or anticardiolipin), had a relative risk of 10.6 for developing restenosis in the first year after PTCA.