Lipid-lowering agents and the risk of hip fracture in a Medicaid population.

CONTEXT: Three recent nested case-control studies conducted in automated databases suggest that users of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have a risk of hip and other osteoporotic fractures half that of non-users of any lipid-lowering drug. However, this comparison may be biased by unmeasured factors associated with treated hyperlipidemias. OBJECTIVE: To compare the risk of hip fracture among users of statins and other lipid-lowering agents, which is less susceptible to bias than the comparisons performed in the previous studies. DESIGN AND SETTING: Retrospective cohort study conducted in the Tennessee Medicaid program between 1 January 1989 through 31 December 1998. SUBJECTS: New users of all lipid-lowering drugs and randomly selected non-user controls who at baseline were at least 50 years of age and did not have life threatening illness, nursing home residence, or diagnosed dementia or osteoporosis. There were 12506 persons with new use of statins, 4798 with new use of other lipid lowering drugs, and 17280 non-user controls. MAIN OUTCOME MEASURE: Fracture of the proximal femur (hip), excluding pathological fractures or those resulting from severe trauma. RESULTS: During 66690 person years of follow up, there were 186 hip fractures (2.8 per 1000). Relative to non-users, the adjusted incidence rate ratios (95% confidence interval) were 0.62 (0.45 to 0.85) for statin users and 0.44 (0.26 to 0.95) for other lipid-lowering drugs. When compared directly with the other drugs, the adjusted incidence rate ratio for statins was 1.42 (0.83-2.43). CONCLUSION: These data provide evidence that the previously observed protective effect of statins may be explained by unmeasured confounding factors.

Sialic acid-dependent binding of baculovirus-expressed recombinant antigens from Plasmodium falciparum EBA-175 to Glycophorin A.

The Plasmodium falciparum Erythrocyte Binding Antigen-175, EBA-175, is a soluble merozoite stage parasite protein which binds to glycophorin A surface receptors on human erythrocytes. We have expressed two conserved cysteine-rich regions, region II and region VI, of this protein as soluble His-tagged polypeptides in insect cell culture, and have tested their function in erythrocyte and glycophorin A binding assays. Recombinant region II polypeptides comprised of the F2 sub-domain or the entire region II (F1 and F2 sub-domains together) bound to erythrocytes and to purified glycophorin A in a manner similar to the binding of native P. falciparum EBA-175 to human red cells. Removal of sialic acid residues from the red cell surface totally abolished recombinant region II binding, while trypsin treatment of the erythrocyte surface reduced but did not eliminate recombinant region II binding. Synthetic peptides from three discontinuous regions of the F2 sub-domain of region II inhibited human erythrocyte cell binding and glycophorin A receptor recognition. Immune sera raised against EBA-175 recombinant proteins recognized native P. falciparum-derived EBA-175, and sera from malaria-immune adults recognized recombinant antigens attesting to both the antigenicity and immunogenicity of proteins. These results suggest that the functionally-active recombinant region II domain of EBA-175 may be an attractive candidate for inclusion in multi-component asexual blood stage vaccines.

Analysis of human antibodies to erythrocyte binding antigen 175 of Plasmodium falciparum.

Invasion of human erythrocytes by Plasmodium falciparum merozoites is a multistep process. For many strains of the parasite, part of this process requires that the erythrocyte binding antigen 175 (EBA-175) of the merozoite binds to sialic acid residues of glycophorin A on the erythrocyte surface, a receptor-ligand interaction which represents a potential target for inhibition by antibodies. This study characterizes the reactivity of naturally acquired human antibodies with four recombinant proteins representing parts of EBA-175 (region II, regions III to V, and the dimorphic C and F segment region) in populations in which the organism is endemic. Serum immunoglobulin G (IgG) recognizing the recombinant proteins is predominantly of the IgG1 and IgG3 subclasses, and its prevalence increases with age. In a large population study in The Gambia, serum positivity for IgG or IgG1 and IgG3 subclass antibodies to each of the EBA-175 recombinant antigens was not significantly associated with subsequent protection from clinical malaria. However, there was a trend indicating that individuals with high levels of IgG to region II may have some protection.

Saccharomyces cerevisiae GATA sequences function as TATA elements during nitrogen catabolite repression and when Gln3p is excluded from the nucleus by overproduction of Ure2p.

Saccharomyces cerevisiae selectively uses good nitrogen sources (glutamine) in preference to poor ones (proline) by repressing GATA factor-dependent transcription of the genes needed to transport and catabolize poor nitrogen sources, a physiological process designated nitrogen catabolite repression (NCR). We show that some NCR-sensitive genes (CAN1, DAL5, DUR1,2, and DUR3) produce two transcripts of slightly different sizes. Synthesis of the shorter transcript is NCR-sensitive and that of the longer transcript is not. The longer transcript also predominates in gln3Delta mutants irrespective of the nitrogen source provided. We demonstrate that the longer mRNA species arises through the use of an alternative transcription start site generated by Gln3p-binding sites (GATAAs) being able to act as surrogate TATA elements. The ability of GATAAs to serve as surrogate TATAs, i.e. when synthesis of the shorter, NCR-sensitive transcripts are inhibited, correlates with sequestration of enhanced green fluorescent protein (EGFP)-Gln3p in the cytoplasm in a way that is indistinguishable from that seen with EGFP-Ure2p. However, when the shorter, NCR-sensitive DAL5 transcript predominates, EGFP-Gln3p is nuclear. These data suggest that the mechanism underlying NCR involves the cytoplasmic association of Ure2p with Gln3p, an interaction that prevents Gln3p from reaching it is binding sites upstream of NCR-sensitive genes.

Overlapping positive and negative GATA factor binding sites mediate inducible DAL7 gene expression in Saccharomyces cerevisiae.

Allantoin pathway gene expression in Saccharomyces cerevisiae responds to two different environmental stimuli. The expression of these genes is induced in the presence of allantoin or its degradative metabolites and repressed when a good nitrogen source (e. g. asparagine or glutamine) is provided. Three types of cis-acting sites and trans-acting factors are required for allantoin pathway gene transcription as follows: (i) UAS(NTR) element associated with the transcriptional activators Gln3p and Gat1p, (ii) URS(GATA) element associated with the repressor Dal80p, and (iii) UIS(ALL) element associated with the Dal82 and Dal81 proteins required for inducer-dependent transcription. Most of the work leading to the above conclusions has employed inducer-independent allantoin pathway genes (e.g. DAL5 and DAL3). The purpose of this work is to extend our understanding of these elements and their roles to inducible allantoin pathway genes using the DAL7 (encoding malate synthase) as a model. We show that eight distinct cis-acting sites participate in the process as follows: a newly identified GC-rich element, two UAS(NTR), two UIS(ALL), and three URS(GATA) elements. The two GATA-containing UAS(NTR) elements are coincident with two of the three GATA sequences that make up the URS(GATA) elements. The remaining URS(GATA) GATA sequence, however, is not a UAS(NTR) element but appears to function only in repression. The data provide insights into how these cis- and trans-acting factors function together to accomplish the regulated expression of the DAL7 gene that is observed in vivo.

No association between calcium channel blocker use and confirmed bleeding peptic ulcer disease.

Calcium channel antagonists are commonly used drugs that have recently been reported to be associated with an increased incidence of gastrointestinal hemorrhage. We performed a retrospective cohort study among 105,824 enrollees of the Tennessee Medicaid program 65 years of age or older between 1984 and 1986. Exposure to calcium channel blockers and other medications was determined from pharmacy files. Hospitalization for bleeding peptic ulcers was identified by hospital claims and verified by a review of the medical record. Univariate estimates of relative risk for current users of calcium channel blockers and beta-blocker users were 1.8 (95% confidence interval (CI) 1.2-2.7) and 1.1 (95% CI 0.7-1.6) (reference group was nonuse of either). After adjustment for potential confounders, the relative risks for bleeding peptic ulcer among current users of calcium channel blockers and beta blockers were 1.1 (95% CI 0.7-1.7) and 1.0 (95% CI 0.7-1.6), respectively, when compared with those who used neither drug. In this population, after controlling for important confounders, there was no increased risk for hospitalization with bleeding peptic ulcer among users of calcium channel blockers.

Baculovirus-mediated expression of Plasmodium falciparum erythrocyte binding antigen 175 polypeptides and their recognition by human antibodies.

The erythrocyte binding antigen EBA-175 is a 175-kDa Plasmodium falciparum protein which mediates merozoite invasion of erythrocytes in a sialic acid-dependent manner. The purpose of this study was to produce recombinant EBA-175 polypeptide domains which have previously been identified as being involved in the interaction of EBA-175 with erythrocytes and to determine whether these polypeptides are recognized by malaria-specific antibodies. The eba-175 gene was cloned by PCR from genomic DNA isolated from the 3D7 strain of P. falciparum. The predicted protein sequence was highly conserved with that predicted from the published eba-175 gene sequences from the Camp and FCR-3 strains of P. falciparum and contained the F segment divergent region. Purified recombinant EBA-175 polypeptide fragments, expressed as glutathione S-transferase fusion proteins in insect cells by using the baculovirus system, were recognized by antibodies present in serum from a drug-cured, malaria-immune Aotus nancymai monkey. The fusion proteins were also recognized by antibodies present in sera from individuals residing in areas where malaria is endemic. In both cases the antibodies specifically recognized the EBA-175 polypeptide portion of the fusion proteins. Antibodies raised in rabbits immunized with the recombinant fusion proteins recognized parasite proteins present in schizont-infected erythrocytes. Our results suggest that these regions of the EBA-175 protein are targets for the immune response against malaria and support their further study as possible vaccine components.

Incidence and risk factors for serious hypoglycemia in older persons using insulin or sulfonylureas.

BACKGROUND: Our knowledge about the risk of hypoglycemia associated with diabetes treatment is derived from studies that often exclude frail, elderly persons. OBJECTIVE: To determine the incidence and risk factors for developing serious hypoglycemia among older persons using sulfonylureas or insulin. METHODS: We conducted a population-based, retrospective cohort study of 19932 Tennessee Medicaid enrollees, aged 65 years or older, who used insulin or sulfonylureas from 1985 through 1989. The main end point was serious hypoglycemia defined as a hospitalization, emergency department admission, or death associated with hypoglycemic symptoms and a concomitant blood glucose determination of less than 2.8 mmol/L (< 50 mg/dL). RESULTS: We identified 586 persons with a first episode of serious hypoglycemia during 33,048 person-years of insulin or sulfonylurea use. The crude rates (per 100 person-years) of serious hypoglycemia were 1.23 (95% confidence interval [CI], 1.08-1.38) in users of sulfonylureas and 2.76 (95% CI, 2.47-3.06) among insulin users. Recent hospital discharge was the strongest predictor of subsequent hypoglycemia in older persons with diabetes. The adjusted relative risk of serious hypoglycemia occurring in days 1 through 30 after hospital discharge was 4.5 (95% CI, 3.5-5.7) compared with the risk associated with a hypoglycemic event occurring 366 or more days after hospital discharge. Other independent risk factors included advanced age (relative risk, 1.8; 95% CI, 1.4-2.3), black race (relative risk, 2.0; 95% CI, 1.7-2.4), and use of 5 or more concomitant medications (relative risk, 1.3; 95% CI, 1.1-1.5). CONCLUSIONS: In this population, the incidence of serious hypoglycemia is approximately 2 per 100 person-years, suggesting that many older adults can be safely treated with hypoglycemic drugs. Frail, elderly persons--the oldest-old, those using multiple medications, and those who are frequently hospitalized--are at a higher risk for drug-associated hypoglycemia. Such individuals may benefit from intensive education about the symptoms of hypoglycemia and close monitoring for adverse events related to diabetes treatment.

Antihypertensives and the risk of serious hypoglycemia in older persons using insulin or sulfonylureas.

CONTEXT: Beta-Blockers and angiotensin-converting enzyme (ACE) inhibitors are effective antihypertensive agents for patients with diabetes mellitus. However, beta-blockers attenuate some components of the autonomic response to hypoglycemia and could increase the risk of hypoglycemia. ACE inhibitors may increase insulin sensitivity and predispose users to hypoglycemia. OBJECTIVE: To determine whether use of cardioselective beta-blockers, nonselective beta-blockers, ACE inhibitors, thiazide diuretics, calcium channel blockers, or other antihypertensive drugs alters the risk of developing serious hypoglycemia among older persons prescribed insulin or sulfonylureas. DESIGN: Retrospective cohort study. SETTING: Tennessee Medicaid Program. PATIENTS: A total of 13,559 elderly (mean age, 78+/-7 years) Medicaid enrollees, who were prescribed insulin (n=5171, 38%) or sulfonylureas (n=8368, 62%) from 1985 through 1989. These enrollees contributed a total of 33,107 person-years of insulin or sulfonylurea use for follow-up. MEASUREMENTS: Hospitalization, emergency department admission, or death associated with hypoglycemic symptoms and a concomitant blood glucose determination of less than 2.8 mmol/L (50 mg/dL). RESULTS: We identified 598 persons with an episode of serious hypoglycemia during the study period. The rate of serious hypoglycemia was 2.01 per 100 person-years among those who were not prescribed antihypertensives. Crude rates of serious hypoglycemia were highest among users of ACE inhibitors (2.47 per 100 person-years) and lowest among users of cardioselective beta-blockers (1.23 per 100 person-years). However, when we controlled for demographic characteristics and markers of comorbidity, there was no statistically significant increase or decrease in risk of serious hypoglycemia among users of any class of antihypertensive agents compared with nonusers of antihypertensive drugs. Using nonselective beta-blockers as the reference group, each of these agents was associated with a lower, but not statistically significant, risk of hypoglycemia. CONCLUSIONS: In this population, specific antihypertensive drug therapy had little impact on the risk of hypoglycemia in older diabetic patients. Therapy should be chosen based on other considerations of safety and effectiveness.

Individual sulfonylureas and serious hypoglycemia in older people.

OBJECTIVE: To compare the risk of serious hypoglycemia associated with the use of individual sulfonylureas in older people. DESIGN: A retrospective cohort study. SETTING: The Tennessee Medicaid Program. PATIENTS: A total of 13,963 Medicaid enrollees, aged 65 years or older, who were prescribed one of six sulfonylureas from 1985 to 1989. MAIN OUTCOME MEASURE: Hospitalization, emergency room admission, or death associated with neuroglycopenic or autonomic symptoms, myocardial infarction, stroke, or injury, with a concomitant blood glucose determination of less than 2.8 mmol/L (50 mg/dL). RESULTS: We identified 255 persons with a first episode of serious hypoglycemia during 20,715 person-years of sulfonylurea use. The crude rate (per 1000 person-years) of serious hypoglycemia was highest in glyburide users, 16.6 (95% confidence interval [CI], 13.2 to 19.9 and lowest among users of tolbutamide, 3.5 (95% CI, 1.2 to 5.9). Users of tolbutamide, tolazamide, and glipizide had lower risks of serious hypoglycemia than users of chlorpropamide, whereas the risk of serious hypoglycemia among glyburide users did not differ from that of chlorpropamide users. Among second generation sulfonylureas, the adjusted relative risk of severe hypoglycemia among glyburide users, compared with glipizide users, was 1.9 (95% CI, 1.2 to 2.9). An increased risk of serious hypoglycemia associated with use of glyburide compared with glipizide occurred in all strata, including those defined by gender, race, nursing home residence, dose, and duration of use. CONCLUSIONS: Significant differences in risk of serious hypoglycemia were observed among users of individual agents. This may be explained by duration, timing, or potency of hypoglycemic action. These data confirm previous findings that chlorpropamide use is associated with high risk of hypoglycemia and indicate that among second generation sulfonylureas, glipizide is less associated with hypoglycemia than is glyburide. More information comparing the effectiveness of glycemic control among individual sulfonylureas is needed to assist prescribers in selecting a specific agent for use in clinical practice.

Nonsteroidal anti-inflammatory drugs and the incidence of hospitalizations for peptic ulcer disease in elderly persons.

To determine the incidence rate of serious ulcer disease among users and nonusers of nonsteroidal anti-inflammatory drugs (NSAIDs), a retrospective cohort study was done on 103,954 elderly Tennessee Medicaid recipients with 209,068 person-years of follow-up from 1984 to 1986. There were 1,371 patients hospitalized with peptic ulcer disease or upper gastrointestinal hemorrhage identified by Medicaid hospital claims and verified by review of the medical record. Ulcer hospitalization rates by NSAID exposure category, duration of use, and daily dose were determined. The rates of ulcer hospitalization among nonusers and current users of NSAIDs were 4.2 and 16.7 per 1,000 person-years, respectively, an excess rate among current users of 12.5 (95% confidence interval (CI) 11.4-13.6) per 1,000 person-years. Among new users, the ulcer hospitalization rates were 26.3 per 1,000 person-years during the first 30 days of use and 20.9 per 1,000 person-years over the next 31-180 days, representing excess ulcer hospitalization rates of 22.1 (95% CI 18.6-25.6) and 16.7 (95% CI 13.1-20.1) per 1,000 person-years, respectively. For long-term users (180 days or more of continuous NSAID use), the ulcer hospitalization rate remained elevated at 15.3, an excess of 12.0 (95% CI 10.3-13.6) hospitalizations per 1,000 person-years. The excess hospitalization rates per 1,000 person-years increased with increasing dose from 6.0 (95% CI 4.0-8.0) for the lowest dose category to 17.8 (95% CI 15.5-20.1) for the highest. The excess rate of ulcer hospitalization for elderly NSAID users is high. These drugs should be used with caution in elderly persons, and alternatives to NSAID therapy should be strongly considered.

UASNTR functioning in combination with other UAS elements underlies exceptional patterns of nitrogen regulation in Saccharomyces cerevisiae.

UASNTR, the UAS responsible for nitrogen catabolite repression-sensitive transcriptional activation of many nitrogen catabolic genes in Saccharomyces cerevisiae, has been previously thought to operate only as a pair of closely related dodecanucleotide sites each containing the sequence GATAA at its core. Here we show that a single UASNTR the unrelated cis-acting element was TTTGTTTAC situated upstream of GLN1, while in another the cis-acting element was the one previously shown to bind the PUT3 protein. When a UASNTR site functions in combination with an unrelated site, the regulatory responses observed are a hybrid consisting of characteristics derived from both the UASNTR site and the unrelated site as well. These observations resolve several significant inconsistencies that have plagued studies focused on elucidation of the mechanisms involved in the global regulation of nitrogen catabolism.

Reserpine reconsidered: no association with serious peptic ulcer disease.

A history of peptic ulcer disease is frequently cited as a contraindication to the use of reserpine. However, the risk of ulcer disease associated with the use of reserpine at current therapeutic doses is unknown. To address this question, the authors conducted a nested case-control study of the association between reserpine use and hospitalizations for peptic ulcer disease in elderly Tennessee Medicaid enrollees. When compared with that of nonusers of reserpine, the relative risk of hospitalization for peptic ulcer disease was 0.8 (95% CI, 0.6-1.0) among current users and 0.8 (95% CI, 0.5-1.3) among former users. The authors' data provide evidence that reserpine is not associated with ulcer disease in elderly persons and suggest that a history of ulcer disease need not be a contraindication to the use of this drug.

Concurrent use of nonsteroidal anti-inflammatory drugs and oral anticoagulants places elderly persons at high risk for hemorrhagic peptic ulcer disease.

BACKGROUND: Although joint use of nonsteroidal anti-inflammatory drugs (NSAIDs) and oral anticoagulants may increase the risk of gastrointestinal tract hemorrhage in elderly persons, no epidemiologic studies have been performed to quantify this risk. METHODS: We performed a retrospective cohort study of Tennessee Medicaid enrollees aged 65 years or older from 1984 through 1986. A total of 103,954 individuals contributed 209,066 person-years of follow-up, including 2203 person-years of current oral anticoagulant use, to the study. RESULTS: Of the cohort members, 1371 had confirmed hospitalizations for peptic ulcer disease. Of these, 661 (48%) presented with frank hematemesis or melena and thus met the definition for hemorrhagic peptic ulcer disease. Among current users of oral anticoagulants, the adjusted incidence of hospitalization for peptic ulcer disease was 14.3 per 1000 person-years, and the adjusted incidence of hospitalization for hemorrhagic peptic ulcer disease was 10.2 per 1000 person-years. Compared with nonusers, current anticoagulant users were at increased risk for hospitalization for ulcer disease (relative risk, 2.2; 95% confidence interval, 1.6 to 3.1), primarily due to the increased risk of hospitalization for hemorrhagic ulcers (relative risk, 3.3; 95% confidence interval, 2.3 to 4.9). Compared with nonusers of either drug, the relative risk of hemorrhagic peptic ulcer disease among current users of both anticoagulants and NSAIDs was 12.7 (95% confidence interval, 6.3 to 25.7). However, the prevalence of NSAID use among anticoagulant users was 13.5%, the same as in those who were not using anticoagulants. CONCLUSIONS: The nearly 13-fold increase in the risk of developing hemorrhagic peptic ulcer disease in concurrent users of oral anticoagulants and NSAIDs suggests that NSAIDs should be prescribed with extreme caution in patients undergoing anticoagulation therapy.

Regulatory circuit for responses of nitrogen catabolic gene expression to the GLN3 and DAL80 proteins and nitrogen catabolite repression in Saccharomyces cerevisiae.

We demonstrate that expression of the UGA1, CAN1, GAP1, PUT1, PUT2, PUT4, and DAL4 genes is sensitive to nitrogen catabolite repression. The expression of all these genes, with the exception of UGA1 and PUT2, also required a functional GLN3 protein. In addition, GLN3 protein was required for expression of the DAL1, DAL2, DAL7, GDH1, and GDH2 genes. The UGA1, CAN1, GAP1, and DAL4 genes markedly increased their expression when the DAL80 locus, encoding a negative regulatory element, was disrupted. Expression of the GDH1, PUT1, PUT2, and PUT4 genes also responded to DAL80 disruption, but much more modestly. Expression of GLN1 and GDH2 exhibited parallel responses to the provision of asparagine and glutamine as nitrogen sources but did not follow the regulatory responses noted above for the nitrogen catabolic genes such as DAL5. Steady-state mRNA levels of both genes did not significantly decrease when glutamine was provided as nitrogen source but were lowered by the provision of asparagine. They also did not respond to disruption of DAL80.

Differentially regulated malate synthase genes participate in carbon and nitrogen metabolism of S. cerevisiae.

We have isolated a second gene (MLS1), which in addition to DAL7, encodes malate synthase from S. cerevisiae. Expression of the two genes is specific for their physiological roles in carbon and nitrogen metabolism. Expression of MLS1, which participates in the utilization of non-fermentable carbon sources, is sensitive to carbon catabolite repression, but nearly insensitive to nitrogen catabolite repression. DAL7, which participates in catabolism of the nitrogenous compound allantoin, is insensitive to carbon catabolite repression, but highly sensitive to nitrogen catabolite repression. Results obtained with null mutations in these genes suggest that S. cerevisiae contains at least one and perhaps two additional malate synthase genes.

Opioid analgesics and the risk of hip fracture in the elderly: codeine and propoxyphene.

We studied the risk of hip fracture in elderly persons receiving prescriptions for two commonly prescribed opioid analgesics--codeine and propoxyphene. Using automated prescription and hospitalization data, we identified 4,500 residents of Saskatchewan, Canada, aged 65 or older, who sustained a hip fracture between 1977 and 1985, and 24,041 age- and sex-matched controls. Compared to nonusers, the relative risk (95% CI) of hip fracture in current users of codeine or propoxyphene was 1.6 (1.4-1.9). There was no difference between relative risks of fracture among current users of codeine [1.6 (1.3-1.9)] and propoxyphene [1.6 (1.2-2.2)]. In new users of these opioids, the relative risk of fracture was 2.2 (1.7-2.8), compared to 1.3 (1.0-1.6) in users who received at least one additional prescription for codeine or propoxyphene in the 90-day period prior to the index date. Concurrent users of these opioids and psychotropic drugs (sedatives, antidepressants, or antipsychotics) had a risk of fracture 2.6 (2.0-3.4) times that of nonusers of either drug class. Review of a sample of medical records for 701 cases suggested this finding was not due to confounding by body mass, ambulatory status, functional status, or dementia. Given the essential role of opioids in the management of pain in geriatric practice, further study is needed to determine the psychomotor effects of opioid analgesics in older adults.

No increased risk for invasive bacterial infection found following diphtheria-tetanus-pertussis immunization.

During the acellular pertussis vaccine trial in Sweden, 4 children who were randomly assigned to receive the vaccine died of suspected or confirmed bacterial infections compared to 1 expected. There were no deaths in the placebo arm. This raised concern about the role of pertussis immunization in the development of serious infections. Through linking computerized immunization records with an active surveillance system for serious bacterial infections in children, the authors studied a cohort of 64,591 children immunized through Tennessee county health clinics who had a total of 158 episodes of invasive bacterial infections after a diphtheria and tetanus toxoids and pertussis (DTP) immunization. There were 8 invasive bacterial infections that occurred within the first 7 days following DTP immunization, yielding an age-adjusted relative risk (95% confidence interval) of 1.0 (0.5 to 2.0), compared to the interval 29 or more days following immunization. There were 7 and 20 infections in the 8- through 14- and 15- through 28-day intervals following DTP immunization, giving relative risks of 0.8 (0.4 to 1.7) and 1.2 (0.7 to 1.9), respectively. These data provide reassurance that the use of DTP vaccine is not followed by a large increased risk of serious bacterial infections.

Upstream induction sequence, the cis-acting element required for response to the allantoin pathway inducer and enhancement of operation of the nitrogen-regulated upstream activation sequence in Saccharomyces cerevisiae.

Expression of the DAL2, DAL4, DAL7, DUR1,2, and DUR3 genes in Saccharomyces cerevisiae is induced by the presence of allophanate, the last intermediate of the allantoin degradative pathway. Analysis of the DAL7 5'-flanking region identified an element, designated the DAL upstream induction sequence (DAL UIS), required for response to inducer. The operation of this cis-acting element requires functional DAL81 and DAL82 gene products. We determined the DAL UIS structure by using saturation mutagenesis. A specific dodecanucleotide sequence is the minimum required for response of reporter gene transcription to inducer. There are two copies of the sequence in the 5'-flanking region of the DAL7 gene. There are one or more copies of the sequence upstream of each allantoin pathway gene that responds to inducer. The sequence is also found 5' of the allophanate-inducible CAR2 gene as well. No such sequences were detected upstream of allantoin pathway genes that do not respond to the presence of inducer. We also demonstrated that the presence of a UIS element adjacent to the nitrogen-regulated upstream activation sequence significantly enhances its operation.