Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Sugammadex-Induced Anaphylactic Shock Reversed With Short-Term Continuous Veno-Venous Hemodiafiltration: A Case Report

Anaphylaxis is a life-threatening, systemic, hypersensitivity reaction, manifested by urticaria, hypotension, and respiratory symptoms. Antigens that are cleared renally may have protracted exposure in patients with impaired renal function, resulting in prolonged and refractory anaphylactic shock. After administration of sugammadex, a 47-year-old man developed prolonged, refractory anaphylactic shock, with anuria due to acute kidney injury. The patient was treated with continuous, short-term, veno-venous hemodiafiltration. Initiating this therapy in patients with refractory anaphylactic shock and anuria due to an antigen that is excreted renally can expedite recovery.

Tumor Satellites Are Associated With Poor Outcome in Patients With Oral Cancer

OBJECTIVES

Tumor satellites are defined as islands of tumor cells completely separated from the border of the main tumor. They are believed to be a sign of aggressive disease. Our goal was to investigate the association between tumor satellites and outcome in patients with oral squamous cell carcinoma.

MATERIALS AND METHODS

A retrospective analysis of all patients treated for oral squamous cell carcinoma at a university-affiliated tertiary care center between 2010 and 2018 was performed. Data collected included demographics, clinical and pathological features including tumor satellites, staging, treatment modalities, and outcomes.

RESULTS

A total of 144 patients were included. The mean age of all patients was 63.5 and 50.7% were males. The mean follow-up time was 40.5 months. Seventeen patients (11.8%) had tumor satellites. These patients had a higher rate of involved margins, peri-neural invasion, lympho-vascular invasion, and extra-nodal extension. Tumor, nodal and overall classification were significantly more advanced in patients with satellites. Disease-specific and overall survival rates were significantly lower among satellites patients (28.7% vs. 59.7% and 28.7% vs. 54.9%, respectively).

CONCLUSIONS

Tumor satellites are associated with several adverse features and advanced locoregional disease. Patients with satellites should be treated aggressively with a combination of surgery aimed at achieving free surgical margins and adjuvant treatment, as they have a worse prognosis compared with patients without satellites. Further prospective studies are mandatory to consolidate the importance of adjuvant treatment in these patients.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:336-343, 2023.

Photochemical processes induced by vibrational overtone excitations: dynamics simulations for cis-HONO, trans-HONO, HNO3, and HNO3-H2O

Photochemical processes in HNO3, HNO3-H2O, and cis- and trans-HONO following overtone excitation of the OH stretching mode are studied by classical trajectory simulations. Initial conditions for the trajectories are sampled according to the initially prepared vibrational wave function. Semiempirical potential energy surfaces are used in "on-the-fly" simulations. Several tests indicate at least semiquantitative validity of the potential surfaces employed. A number of interesting new processes and intermediate species are found. The main results include the following: (1) In excitation of HNO3 to the fifth and sixth OH-stretch overtone, hopping of the H atom between the oxygen atoms is found to take place in nearly all trajectories, and can persist for many picoseconds. H-atom hopping events have a higher yield and a faster time scale than the photodissociation of HNO3 into OH and NO2. (2) A fraction of the trajectories for HNO3 show isomerization into HOONO, which in a few cases dissociates into HOO and NO. (3) For high overtone excitation of HONO, isomerization into the weakly bound species HOON is seen in all trajectories, in part of the events as an intermediate step on the way to dissociation into OH + NO. This process has not been reported previously. Well-established processes for HONO, including cis-trans isomerization and H hopping are also observed. (4) Only low overtone levels of HNO3-H2O have sufficiently long liftimes to be spectrocopically relevant. Excitation of these OH stretching overtones is found to result in the dissociation of the cluster H hopping, or dissociation of HNO3 does not take place. The results demonstrate the richness of processes induced by overtone excitation of HNO(x) species, with evidence for new phenomena. Possible relevance of the results to atmospheric processes is discussed.

New Experimental and Theoretical Approach to the Heterogeneous Hydrolysis of NO2: Key Role of Molecular Nitric Acid and Its Complexes

Although heterogeneous chemistry on surfaces in the troposphere is known to be important, there are currently only a few techniques available for studying the nature of surface-adsorbed species as well as their chemistry and photochemistry under atmospheric conditions of 1 atm pressure and in the presence of water vapor. We report here a new laboratory approach using a combination of long path Fourier transform infrared spectroscopy (FTIR) and attenuated total reflectance (ATR) FTIR that allows the simultaneous observation and measurement of gases and surface species. Theory is used to identify the surface-adsorbed intermediates and products, and to estimate their relative concentrations. At intermediate relative humidities typical of the tropospheric boundary layer, the nitric acid formed during NO2 heterogeneous hydrolysis is shown to exist both as nitrate ions from the dissociation of nitric acid formed on the surface and as molecular nitric acid. In both cases, the ions and HNO3 are complexed to water molecules. Upon pumping, water is selectively removed, shifting the NO(3-)-HNO3(H2O)y equilibria toward more dehydrated forms of HNO3 and ultimately to nitric acid dimers. Irradiation of the nitric acid-water film using 300-400 nm radiation generates gaseous NO, while irradiation at 254 nm generates both NO and HONO, resulting in conversion of surface-adsorbed nitrogen oxides into photochemically active NO(x). These studies suggest that the assumption that deposition or formation of nitric acid provides a permanent removal mechanism from the atmosphere may not be correct. Furthermore, a potential role of surface-adsorbed nitric acid and other species formed during the heterogeneous hydrolysis of NO2 in the oxidation of organics on surfaces, and in the generation of gas-phase HONO on local to global scales, should be considered.

Ab Initio Vibrational Calculations for H2SO4 and H2SO4·H2O: Spectroscopy and the Nature of the Anharmonic Couplings

Vibrational frequencies for fundamental, overtone, and combination excitations of sulfuric acid (H2SO4) and of sulfuric acid monohydrate cluster (H2SO4 x H2O) are computed directly from ab initio MP2/TZP potential surface points using the correlation-corrected vibrational self-consistent field (CC-VSCF) method, which includes anharmonic effects. The results are compared with experiment. The computed transitions show in nearly all cases good agreement with experimental data and consistent improvement over the harmonic approximation. The CC-VSCF improvements over the harmonic approximation are largest for the overtone and combination excitations and for the OH stretching fundamental. The agreement between the calculations and experiment also supports the validity of the MP2/TZP potential surfaces. Anharmonic coupling between different vibrational modes is found to significantly affect the vibrational frequencies. Analysis of the mean magnitude of the anharmonic coupling interactions between different pairs of normal modes is carried out. The results suggest possible mechanisms for the internal flow of vibrational energy in H2SO4 and H2SO4 x H2O.

Häufigkeit psychischer Auffälligkeiten und Begleitsymptome bei drei- bis sechsjährigen Kindern: Ergebnisse der Braunschweiger Kindergartenstudie

Zusammenfassung: Fragestellung: Im Rahmen der Braunschweiger Kindergartenstudie wurde die Häufigkeit psychischer Auffälligkeiten und Begleitsymptome bei Kindern im Alter zwischen 3 und 6 Jahren untersucht. Methode: Die Untersuchung wurde im November 1998 in allen städtischen Kindertagesstätten Braunschweigs mit einer leicht modifizierten Version des Elternfragebogens über das Verhalten von Kindern und Jugendlichen/CBCL 4-18 durchgeführt. Von N = 809 Kindern liegen Elterneinschätzungen vor. Ergebnisse: Die Prävalenzraten für psychische Störungen bei Kindergartenkindern liegen zwischen 0,5% und 5,0%, wobei in dieser Altersgruppe Aggressives Verhalten, Aufmerksamkeitsprobleme und Soziale Probleme am häufigsten auftreten. Es werden außerdem Komorbiditätsraten für die einzelnen Syndromskalenpaare der CBCL berichtet. Diskussion: Abschließend werden die vorliegenden Ergebnisse mit anderen Untersuchungen verglichen und Implikationen vor allem für die Prävention kindlicher Verhaltensauffälligkeiten diskutiert.

The emergence of Streptococcus pneumoniae resistant to macrolide antimicrobial agents: a 6-year population-based assessment

From 1994 through 1999, the available isolates (4148 isolates) from active population-based surveillance of invasive pneumococcal disease in metropolitan Atlanta were serotyped and were tested for antimicrobial susceptibility. Macrolide-resistant isolates were studied for the presence of ermAM (a ribosomal methylase gene), mefE (a macrolide efflux gene), and tetM (the class M tetracycline resistance gene). Macrolide resistance increased from 16% of all invasive isolates in 1994 to 32% in 1999. Of the macrolide-resistant pneumococcal isolates studied, 99% contained genomic copies of mefE or ermAM. Isolates with ermAM were mainly serotypes 6B, 23F, 14, or 19F and contained tetM; mefE-associated isolates were predominantly serotypes 14, 6A, or 19F, and most did not contain tetM. The frequency of the ermAM-mediated phenotype in invasive Streptococcus pneumoniae remained stable over the 6-year surveillance. However, the mefE-mediated phenotype increased from 9% in 1994 to 26% of all isolates in 1999 and was noted in new serotypes. By 1999, 93% of the mefE-containing strains had minimum inhibitory concentrations >/=8 microgram/mL. Dissemination of the mefE determinant accounted for the rapid increase in the rate of macrolide resistance in our S. pneumoniae population.

Screening for lung cancer revisited and the role of sputum cytology and fluorescence bronchoscopy in a high-risk group

Lung cancer is an epidemic disease that is underrepresented in the research funding for early detection and chemoprevention arenas. Screening programs have been discouraged for both financial and political reasons. Yet, increasing evidence suggests that screening and early detection may improve outcome in lung cancer. Sputum cytology examination has been shown in several studies to lead to detection of lung cancer at an earlier stage, resulting in an improved 5-year survival rate. Monoclonal antibody detection, fluorescence bronchoscopy, and low-dose spiral CT increase diagnostic sensitivity and improve the ability to localize early-stage lesions. Utilizing these new techniques and improving the definition of high-risk groups may improve the success and cost-effectiveness of early detection based on sputum cytology. The ultimate goal of improving long-term survival in lung cancer will be achieved only when cancer can be detected in its early stages and lesions can be localized in large numbers. Advances in the last 15 years offer an encouraging vision for the value of early detection and effective treatment for lung cancer.

Nonconstitutive expression of the gastrin-releasing peptide autocrine growth system in human small cell lung carcinoma NCI-H345 cells

Constitutive, unregulated autocrine growth is thought to be an important mechanism whereby cancer cells gain a proliferative advantage over nonmalignant cells. The question addressed here was whether the autocrine growth system for gastrin-releasing peptide (GRP) in human small cell lung carcinoma cells is, in fact, always expressed in a constitutive, unregulated fashion. Lag, rapid, and plateau growth states were defined for small cell lung carcinoma NCI-H345 cells based on periods during which they expressed different growth rates after plating as single cell suspensions. Immunoreactive GRP in the conditioned medium and in NCI-H345 cells harvested during each of these growth states, as well as cell DNA content, GRP mRNA expression, specific 125I-GRP uptake, specific 125I-GRP binding to solubilized membranes, and GRP and neuromedin B receptor mRNA expression by reverse transcription-PCR were analyzed. Maximal levels of GRP expression were observed during the lag growth state, with the highest concentration of immunoreactive GRP in the conditioned medium during the rapid growth state. Specific 125I-GRP uptake and binding were also highest during the lag growth state; however, GRP receptor mRNA did not significantly change. In contrast to prevailing concepts, these studies support the conclusion that the expression of the GRP autocrine growth system in NCI-H345 cells is indeed regulated. Furthermore, the components are maximally expressed before rapid growth begins, suggesting that other mechanisms are activated to support the actual proliferation.

Subjectively reported oral health status in an adult population

This study describes the subjectively reported oral health status of an adult population aged 18 yr and over. The study used measures of the functional, social and psychological impact of oral disorders, originally developed for surveys of older adults, and aimed to determine whether or not they were sensitive to the oral health concerns of younger adults. It compared four age groups (18-29 yr; 30-49 yr; 50-64 yr; 65 yr and over) in terms of the following subjective oral health indicators: ability to chew, problems speaking, oral and facial pain; other oral symptoms; problems eating; problems with communication-social relations; limitations in activities of daily living and worry and concern. The initial hypothesis that few younger subjects would report the kinds of problems documented by these indicators was not supported. On all measures except ability to chew, younger subjects were as likely to be compromised by oral conditions as older subjects.

Isolation of two contigs of overlapping cosmids derived from human chromosomal band 3p21.1 and identification of 5 new 3p21.1 genes

Consistent loss of DNA sequences from several regions on the short arm of human chromosome 3 has suggested that multiple tumor suppressor genes reside on chromosome 3p in various types of cancer cells. We have focused our efforts on an analysis of chromosomal band 3p21.1 since aminoacylase-1 (ACY1), which is localized to this band, has been shown to have lower levels of expression in several small cell and non-small cell lung cancer cell lines. Starting with two cosmids within 3p21.1, D3S92 and D3S93, we have isolated two separate contigs of overlapping cosmids within 3p21.1, by screening a library of 5700 chromosome 3-specific cosmid clones. Detailed restriction maps for these two contigs show that they contain multiple clusters of rare cutting restriction endonuclease sites. One contig extends for 100 kb and encompassed both ACY1 and D3S92, and the other extends about 80 kb around the D3S93 locus. Many different restriction fragments derived from these two contigs were found to be evolutionarily conserved and hybridized to distinct message transcripts. These fragments were used to identify homologous cDNAs from an adenogastric cDNA library, and several of these cDNAs were partially sequenced. We have identified five new genes from these two contigs and there is evidence to suggest that several additional genes reside within these cosmid contigs. The genes identified from 3p21.1 were then hybridized to DNA, isolated from a series of lung cancer cell lines and matched normal and tumor DNA from lung cancer patients. No alterations were detected with any of these probes, both at the DNA or RNA levels. A similar analysis with DNA fragments derived from these two genomic regions also failed to detect any alterations.

Correlates of tooth loss in a Canadian adult population

Oral health data collected from a mail survey of an Ontario population of adults aged 18 years and over were used to conduct a preliminary investigation of the incidence and correlates of tooth loss and to explore its functional, psychological and social consequences. Of the sample of 500 dentate subjects, 10 per cent reported losing one or more teeth in the previous year. Comparisons between those with and without tooth loss showed significant differences according to age, household income and place of birth. Those subjects wearing partial dentures, possessing fewer teeth at the start of the study period, or who only attended the dentist when having pain or other trouble, were also more likely to have experienced tooth loss in the preceding year. Logistic regression analysis identified only age as a significant independent risk factor. Subjects who lost teeth were significantly more compromised in their oral functions and psychosocial behaviors, as measured by a battery of subjective oral health indicators. Whether or not these problems were pre-existing or the consequences of losing teeth during the past year cannot be determined from this study. This investigation suggests that tooth loss is still a concern for many Canadian adults, and demonstrates the importance of teeth in their overall well-being.

Evaluation of subjective oral health status indicators

OBJECTIVES

This paper reports the results of a study to evaluate the performance of a battery of subjective oral health status indicators originally developed for use in large scale surveys of older adults. The aim was to assess their generalizability, efficiency, reliability, and validity when used in a study of adults aged 18 years and over and to compare their performance with respect to younger and older adults.

METHODS

Data were collected by means of a mail survey and self-complete questionnaire of a random sample of the population aged 18 years and older.

RESULTS

The results suggested that the measures were sensitive to the oral health concerns of adults of all ages and that item nonresponse was within acceptable limits. Test-retest and internal consistency reliability statistics were good and all hypotheses designed to assess concurrent and construct validity were confirmed.

CONCLUSIONS

The results confirm an earlier, but more limited, evaluation and suggest that these indicators are useful for descriptive oral health surveys of general populations.

Development of a novel human extracellular matrix for quantitation of the invasiveness of human cells

During the crucial stages of tumor cell invasion and metastasis, neoplastic cells must traverse extracellular matrices for their migration to distant sites. Because basement membranes (BM) serve as a critical barrier to such passages, most previous in vitro assay models have utilized either an intact BM or a reconstituted rodent or avian BM-matrix to study this process. We have created a gel-like extracellular matrix derived from human amnions which contained type IV collagen, laminin, entactin, tenascin and heparan sulfate proteoglycan. This matrix, which we called Amgel, was used to study selected steps of invasion including cell attachment to matrix, degradation of it by proteolytic enzymes and movement of human tumor cells through matrix defects. An efficient tumor invasion assay system was developed utilizing filter-supported uniform coatings of this matrix in chambers. Human tumor cells (HT-1080 fibrosarcoma and RL-95 adenocarcinoma), when seeded onto Amgel-coated membranes, attached to matrix within 2 h and initiated a time-dependent migration and invasion process, as verified by biochemical analysis and both light and electron microscopy. In an optimized invasion assay 12-15% of tumor cells completely traversed the matrix during a 72-h period with > 90% viability. In contrast to these highly-invasive cells, normal human foreskin fibroblasts and normal human endometrial stromal cells exhibited minimal migration/matrix penetration during the same time period. When the Amgel-selected tumor cells (i.e. those penetrating the barrier) were isolated, subcultured, and re-exposed to Amgel, they had heightened invasiveness (2-3-fold) as compared to the parental cells. Thus, this improved 'all human' system for quantitating the invasive ability of tumor cells may provide a valuable tool in dissecting out the mechanistic underpinnings of human metastasis. In addition, this assay has the ability to screen agents which have potential anti-invasive and by extension anti-metastatic, activity or chemotactic properties.

Coping responses in depressed, socially maladjusted, and suicidal adolescents

To study the relation between specific coping-response preferences and three dimensions of psychological disturbance in adolescents, 41 adolescents who had been admitted to an inpatient psychiatry program completed measures of depression, social maladjustment, suicidality, and coping responses to stressful life events. Analysis indicated that lower affective regulation was associated with increased depression, higher emotional discharge was associated with increased social maladjustment, and lower problem solving was associated with suicide attempts.

A 2.5-Mb physical map within 3p21.1 spans the breakpoint associated with Greig cephalopolysyndactyly syndrome

Numerous investigations suggest that one or more genes residing in the p14 to p21 region of human chromosome 3 are critical to the development of neoplastic diseases such as renal cell carcinoma and small-cell lung cancer (SCLC). This region is additionally involved in several interchromosomal translocations, one of which is associated with the developmental disorder Greig cephalopolysyndactyly syndrome. A series of five loci that map in close proximity to the Greig syndrome breakpoint [t(3;7)(p21.1;p13)] at 3p21.1 have been physically linked by pulsed-field gel analysis over a 2.5-Mb region. The probes include ACY1, cA84 (D3S92), cA199 (D3S93), pHF12-32 (D3S2), and MW-Not153 (D3S332). The Greig 3;7 translocation breakpoint was discovered between clones cA199 and MW-Not153, separated by 825 kb. Further analysis revealed comigration of a rearranged fragment detected by MW-Not153 and a chromosome 7 probe previously shown to be in close proximity to the breakpoint (CRI-R944). This latter probe also detects a rearrangement in a second Greig-associated translocation, (6;7)(q27;p13). The physical map resulting from this analysis orders the markers along the chromosome and identifies several locations for CpG islands, likely associated with genes. Although probe pEFD145.1 (D3S32) has been genetically linked to D3S2 (2 cM), physical linkage to the other five loci could not be demonstrated. One of the linked loci, D3S2, has been widely utilized in the analysis of chromosome 3p loss in several malignant diseases. Since expression of ACY1, a housekeeping gene, is specifically reduced in many cases of SCLC, knowledge of its precise chromosomal position and identification of neighboring putative gene loci should facilitate investigation into the mechanism of this reduction.

The p97 antigen is mapped to the q24-qter region of chromosome 3; the same region as the transferrin receptor

Since the p97 antigen, a membrane-associated iron-binding protein, has extensive amino acid sequence with homology with transferrin, is functionally related to the transferrin receptor, and has been previously mapped to chromosome 3, we have performed additional studies for regional mapping of the gene expressing p97 antigen. In these experiments, Chinese hamster-human cell lines were chosen that contained a large spectrum of autosomal human chromosomes, but mainly consisted of clones expressing all or a part of chromosome 3. These cell lines included a clone that previously allowed for mapping of human transferrin receptor to q22-qter region. Human p97 expression was assessed by specific binding of [125I]monoclonal antibody 96.5, and human transferrin receptor expression was tested by specific [125I]human transferrin binding and [125I]monoclonal antibody OKT-9 specific for human transferrin receptor. Based on these analyses, both human p97 antigenic expression and human transferrin receptor are mapped concordantly to the q24-qter region. These data and previous reports, therefore, suggest that the related iron-transport proteins are closely linked and may be under coordinate regulation. However, studies of several cell lines that exhibit up-regulation of human transferrin receptor expression with cellular proliferation, and down-regulation of receptor with increased transferrin-iron in the media, showed no change in expression of p97 antigen. p97 antigenic expression increased when melanocyte-stimulating hormone was added to a human melanoma cell line in tissue culture. These latter studies suggest that in mammalian cells the two proteins do not show coordinate regulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural gene coding for multifunctional protein carrying orotate phosphoribosyltransferase and OMP decarboxylase activity is located on long arm of human chromosome 3

In humans, deficiency in the last two enzymes of UMP biosynthesis, orotate phosphoribosyltransferase (OPRT) and OMP decarboxylase results in the inborn error of metabolism hereditary orotic aciduria, type 1. In this manuscript, we present immunologic, molecular, biochemical, and genetic evidence that the gene coding for this set of enzymatic activities is located on the long arm of human chromosome 3. The evidence presented here is consistent with both these activities being carried on the same multifunctional protein in mammalian cells. These studies allow further genetic analysis of human chromosome 3, confirming that human markers ACY-1, previously assigned to 3p21, and beta-gal, previously assigned by others to the region 3(p21-q21), must be in the region 3 (cen-p21) and confirming the regional assignment of a human DNA segment, D3S1, to 3q12. The significance of these studies to genetic analysis of genes on human chromosome 3, some of which appear to play a role in some forms of malignancy, is discussed.

Differential response of chlamydial and ureaplasma-associated urethritis to sulphafurazole (sulfisoxazole) and aminocyclitols

91 men with non-gonococcal urethritis (N.G.U.) were randomly treated with either sulphafurazole (sulfisoxazole), 500 mg orally q.i.d. for 10 days, or an aminocyclitol (streptomycin or spectinomycin), 2 g intramuscularity for 1 to 3 doses at 12 h intervals. Initial urethral cultures were positive for Chlamydia trachomatis (C) in 36 (40%). Ureaplasma urealyticum (U) was isolated from the urethra or urine from20 (95%) of 21 White men in a first episode of N.G.U. who had negative chlamydia cultures. Sulphafurazole, active against C. trachomatis but not U. urealyticum in vitro, produced a clinical response in 7 of 7 men with C+U- N.G.U. and 5 of 19 with C-U+ N.G.U. (P less than 0-01). Aminocyclitols, active against U. urealyticum but relatively inactive against C. trachomatis in vitro produced a clinical response in 0 of 6 men with C+U-N.G.U., 9 of 11 men with C-U+N.G.U. from whom ureaplasma was eradicated (P less than 0-01), and 0 of 8 with C-U+ N.G.U. from whom ureaplasma was not eradicated. C+U+ N.G.U. responded poorly to both antimicrobials alone. These results support the aetiological importance of both C. trachomatis and U. urealyticum in N.G.U.