Complete detection of mutations in cystic fibrosis patients of Native American origin

An increased incidence of cystic fibrosis (CF) has been reported in some populations of Native Americans of the Southwest such as the Pueblo, which is a genetic isolate. As the most common mutation found in Caucasians (delta F508) was absent and only one chromosome carried the G542X mutation, we decided to analyze the entire coding sequence of the CFTR gene in eight Pueblo CF patients. We have identified four different mutations: G542X, R1162X, 3849+10kbC-->T, and D648V that account for these 16 haplotypes. The R1162X was found on 11 chromosomes. Using intragenic microsatellites, we have compared the haplotypes of those chromosomes to those of Italian origin where the R1162X mutation was initially reported. These haplotypes turned out to be identical, suggesting a common origin and an admixture with Italian or Spanish settlers, followed by typical founder effect. In contrast the 3849+10kbC-->T mutation, which was found on three chromosomes, is associated with different haplotypes than those on chromosomes carrying the same mutation in Caucasians. A novel mutation, D648V, observed on one chromosome has not been found outside the Pueblo population.

Incidence, management, and outcome of femoral shaft fracture: a statewide population-based analysis of 2805 adult patients in a rural state

Early surgical management of femoral shaft fracture (FSF) is considered the standard but patients are still treated nonsurgically. The purpose of this study was to analyze the results of management of FSF in a large population based data base.

METHODS

Data were obtained from a statewide hospital discharge data base for 1989-1992. Adults having a FSF were stratified by ISS (ISS < 15 vs. ISS > or = 15) and management (nonsurgical, surgery within 1 day, surgery at 2-4 days, or surgery at > 4 days). Mortality rates and mean length of hospital stay were compared among groups.

RESULTS

2805 patients had FSFs: 69% were managed surgically and 31% nonsurgically. Mortality was higher for nonsurgical therapy in both ISS groups. In the surgically treated groups, length of hospitalization increased as delay to surgery increased. In patients with an ISS > or = 15, repair at 2-4 days was associated with the lowest mortality and shortest hospitalization, while a trend to higher mortality and longer hospitalization was noted with repair within 1 day.

CONCLUSION

31% of patients were treated nonsurgically with higher associated mortality. These results support "early" surgical fixation, which can shorten hospital stay without increasing mortality regardless of overall injury severity. The trend toward higher mortality in severely injured patients operated on within 1 day of admission suggests that this group warrants further study and individualized management.

Transmission of human T cell lymphotropic virus (HTLV) type II by transfusion of HTLV-I-screened blood products

Blood donors have been screened for antibodies to human T cell lymphotropic virus (HTLV) type I since December 1988. Screening for HTLV-II has been simultaneously done because of cross-reactivity between antibodies to the two viruses. Currently, < 1 in 10,000 US blood donors is positive for HTLV-I or -II. Lookback studies led to the identification of 6 HTLV-II-infected patients. Three received transfusions before introduction of HTLV-I screening tests, while the other 3 received blood components that tested negative for HTLV-I. The HTLV-II subtypes of each of 4 donor/recipient pairs, as determined by DNA amplification using polymerase chain reaction, were identical, supporting the view that transfusions were the source of infection. In conclusion, currently licensed blood donor screening tests for HTLV-I lack sensitivity for HTLV-II, and transfusion of blood from HTLV-II-infected donors that test negative on HTLV-I screening tests may result in infection.

Cloning and characterization of the altA alpha-tubulin gene of Physarum

A cDNA clone derived from the altA locus, encoding one of several alpha-tubulins in Physarum, was sequenced and used to determine the developmental and cell cycle expression patterns of its corresponding gene. The predicted amino acid sequence of the altA gene product, alpha 1A-tubulin, is 92% identical to the other known Physarum alpha-tubulins, alpha 1B and alpha 2B, which are products of two tightly linked genes at the altB locus. The nucleotide sequence of the altA coding region is 82% identical to the two altB genes. Expression of the altA gene was found in all three cell types examined - amoeba, flagellate and plasmodium - but at substantially different levels in each. The peak level of altA message detected in flagellates was 14-fold higher than in amoebae, while the peak level in plasmodia was 5-fold lower than in amoebae. The expression pattern of altA and the predicted amino acid sequence of the alpha-tubulin it encodes suggest that alpha 1A is the substrate for post-translational acetylation, giving rise to the alpha 3-tubulin isoform found specifically in amoebae and flagellates. Northern blot analysis of plasmodial RNA samples from specific times in the cell cycle showed that the level of altA message varies over the cell cycle in a pattern similar to transcripts from other tubulin genes, with a peak at mitosis and little or no message detected during most of interphase.

Ultrastructure and pyruvate formate-lyase radical quenching property of the multienzymic AdhE protein of Escherichia coli

The AdhE protein of Escherichia coli is a homopolymer of 96-kDa subunits harboring three Fe(2+)-dependent catalytic functions: acetaldehyde-CoA dehydrogenase, alcohol dehydrogenase, and pyruvate formatelyase (PFL) deactivase. By negative staining electron microscopy, we determined a helical assembly of 20-60 subunits into rods of 45-120 nm in length. The subunit packing is widened along the helix axis when Fe2+ and NAD are present. Chymotrypsin dissects the AdhE polypeptide between Phe762 and Ser763, thereby retaining the alcohol dehydrogenase activity on the NH2-terminal core, but destroying all other activities. PFL deactivation, i.e. quenching of the glycyl radical in PFL by the AdhE protein, was examined with respect to cofactor involvements (Fe2+, NAD, and CoA). This process is coupled to NAD reduction and requires the intact CoA sulfhydryl group. Pyruvate and NADH are inhibitors that affect the steady-state level of the radical form of PFL in a reconstituted interconversion cycle. Studies of cell cultures found that PFL deactivation in situ is initiated at redox potentials of greater than or equal to +100 mV. Our results provide insights into the structure/function organization of the AdhE multienzyme and give a rationale for how its PFL radical quenching activity may be suppressed in situ to enable effective glucose fermentation.

Prescription for change: an interview with FDA Commissioner Dr. David Kessler

Dr David A. Kessler took over as Commissioner of the Food and Drug Administration in December 1990. Since then, he has initiated many changes to improve the structure and efficiency of the agency. In this interview, he describes some of the problems and challenges associated with the process of reviewing and approving new drugs.

y? Diagram, a powerful optical design method for laser systems

We present a new method for synthesizing and analyzing laser systems based on the use of the y? diagram. The diagram is commonly used to represent two rays, the marginal and the chief rays, as they propagate through an optical system. Since a Gaussian beam can be represented by two rays, it is possible to use the y? diagram to represent these rays. This results in a representation of the beam as a single ray line on the y? diagram with simple graphic interpretations for the beam parameters. An equivalent representation of the Gaussian beam on the uū diagram is also presented and discussed. Complex design problems may be reduced to simple graphic problems, which often lead directly to algebraic solutions. Examples of y? diagrams are given for beam transfer through simple optical systems, including gradient optics. Diagram transformations are discussed and design examples are given of a three-element afocal system and a three-element collimator.

X-linked mental retardation with bilateral clasped thumbs: report of another affected family

A Sephardi Jewish family is reported in which the two brothers had mental retardation, lower limb spasticity and bilateral clasped thumbs anomaly. This X-linked recessive disorder has only been reported twice. We believe this syndrome comprises a distinct entity among the X-linked mental retardation syndromes.

Birth order, family size, and achievement: family structure and wage determination

The influence of birth order and childhood family size on future achievement is discussed. Two major empirical findings are presented by the author. "First, neither birth order nor childhood family size significantly influences the level or growth rate of wages, a result that is consistent with previous research. Second, family size is both a statistically and economically significant determinant of women's employment status: women from small families work less than women from large families when they are young and more than women from large families when they are more mature." The geographical focus is on the United States.

Optimal pension funding with demographic instability and endogenous returns on investment

"This paper tries to explore some optimal funding policies for pension systems in a general equilibrium setting where funding affects returns on investment and wages through its impact on capital formation. This is done in the context of irregular demographic evolutions such as those expected in developed countries for the next century. Particular attention is given to the intergenerational welfare criterion which is used for designing optimal policies.... We will first present the model for the pension system and the economy and discuss a general one-parameter form for the intergenerational utility function. We will then present the simulated optimal paths for different numerical specifications of the model and the utility function. The last section will show by how much a simpler policy with fixed transfers and purely individual funding can depart from optimal paths...."

Pyruvate-formate-lyase-deactivase and acetyl-CoA reductase activities of Escherichia coli reside on a polymeric protein particle encoded by adhE

A 4.8 kb DNA-fragment was cloned and sequenced encompassing the structural gene of PFL-deactivase (2.7 kb) and 2 kb of the 5' flanking region that contains the elements for anaerobic induction. A mutant lacking deactivase was shown to require exogenous electron acceptors for anaerobic growth with glucose. This revealed the identity of PFL-deactivase with the alcohol and acetaldehyde dehydrogenases of E. coli. The multienzyme represents a homopolymeric protein (approximately 40 x 96 kDa) requiring Fe2+ for all functions.

[Extracorporeal support technics in the treatment of multisystem failure. Our experience]

Mortality rate among patients with septic, oliguric, multiple organ failure is high. Conventional hemodialysis has often detrimental effects on critically ill patients. Continuous arteriovenous hemofiltration (CAVH), continuous arteriovenous hemodialysis (CAVH/D) and continuous arteriovenous hemodialysis associated with sequential plasmapheresis (CAVHP/D) could reduce mortality in septic (hypercatabolic, oliguric) ARDS induced MOF patients. These techniques are simple and can be managed without superspecialized personnel.

Use of extracorporeal supportive techniques as additional treatment for septic-induced multiple organ failure patients

We compared retrospectively four similar groups of patients with multiple organ failure (MOF) due to sepsis. All of them were treated initially with conventional therapy, aprotinin as protease inhibitor and vitamin C with allopurinol as possible scavengers of oxygen-free radicals, were also added. After 24 h of no clinical progress, continuous arteriovenous hemofiltration (CAVH), CAVH/dialysis (CAVH/D), and sequential plasmafilter-dialysis with slow continuous hemofiltration (CAVHP/D) were respectively added to groups 2 (n = 14), 3 (n = 6), and 4 (n = 11). Mortality was 87% for group 1, 71% for group 2, 50% for group 3, and 36% for group 4. In the latter we were able to remove possible MOF-inducing mediators from the bloodstream, to give fluids without restriction (even in oliguric patients), and to improve removal of metabolic waste products. It is possible that these extracorporeal supports, associated with conventional therapy, and pharmacologic drugs such as protease inhibitors and possible scavengers of oxygen-free radicals, helped to reduce the mortality rate. We conclude that, although the number of study patients was too small to reach firm conclusions, the good results observed with CAVHP/D suggest clinical trials to assess the efficacy of this technique.

Superimposed high frequency ventilation with conventional mechanical ventilation

A 73-year-old man with ARDS-multiple organ failure due to Chlamydia psittaci, was successively supported with conventional respiratory techniques. After 48 hours of no clinical improvement, HFV was superimposed to CMV in order to combine the advantages of each one. Since improvement has been seen in all ventilatory parameters, this method is suggested as another mode of ventilation for patients with refractory hypoxia and hypercarbia who do not respond to conventional respiratory care.

Case-control study of men with suspected chronic idiopathic prostatitis

We studied prospectively 50 asymptomatic men (24 men from infertile couples and 26 normal volunteers) with no history of genitourinary infection and 34 men referred for symptoms of chronic prostatitis. Both groups were evaluated by urethral and prostatic secretion cultures for Chlamydia trachomatis, 4-glass prostatic localization cultures for facultative aerobic bacteria (Ureaplasma urealyticum, Mycoplasma hominis and selected fungi) and counts of prostatic fluid leukocytes. The men with symptoms of prostatitis had more than 1,000 leukocytes per mm. in prostatic secretions more often than did controls (11 of 27 versus 0 of 44, p less than 0.001). The concentration of Ureaplasma urealyticum in prostatic secretions was 1 log higher in prostatic fluid localization cultures than in first voided urine in 0 of 30 patients versus 13 of 50 controls (p equals 0.0014). Chlamydia trachomatis was not isolated from any patient or control. No other significant differences were found between patients and controls. We did not identify an infectious cause of chronic nonbacterial prostatitis.

ECMO: regional evaluation of need and applicability of selection criteria

The need and indications for neonatal extracorporeal membrane oxygenation (ECMO) are controversial. The need for ECMO in two New England states was studied through a review of deaths due to respiratory failure in near- and full-term infants. Vermont averaged 2.4 and Maine averaged 7.4 deaths annually. Neither state demonstrated sufficient respiratory deaths to establish ECMO capability. The number of "potential" ECMO candidates, based on published selection criteria, was studied, and the applicability of criteria was evaluated. A two-year review revealed 16 potential candidates from Maine and 19 from Vermont. No criterion accurately identified nonsurvivors of conventional ventilatory therapy. Only one criterion in one institution demonstrated an association with chronic lung disease. The data demonstrated that published ECMO selection criteria were not applicable in different populations.

Differential activity of the 30-kD and the 100-kD forms of 2'-5'An synthetase induced by recombinant human interferon-alpha and interferon-gamma

Two molecular weight variants of the interferon (IFN)-induced intracellular enzyme 2',5'-oligoadenylate (2-5A) synthetase have been described recently; a 100-kD (cytoplasmic) and a 30-kD (intranuclear) form of the enzyme. The 30-kD form has been located primarily in the nucleus, while the 100-kD enzyme was found mainly in the cytoplasm. We examined 2-5A synthetase activity in extracts of human melanoma (Hs294t) cells treated with either recombinant (r) IFN-alpha A or rIFN-gamma to determine the differential regulation of these enzyme subtypes by treatment with the two types of IFN. Cells were treated (continuous exposure) with doses of rIFN-alpha A (1,000 U/ml) or rIFN-gamma (5,000 U/ml), each of which reduced the number of viable cells to 50% of control values (ED50) by day 3 of treatment. At equieffective doses, the maximal increase in 2-5A synthetase occurred at 48 h for both rIFN-alpha A and rIFN-gamma continuous exposure. The maximal 2-5A intracellular activities at 48 h were 800 +/- 40 and 160 +/- 15 nmoles/mg protein for rIFN-alpha A and rIFN-gamma treatment, respectively. High-performance gel permeation chromatography of cell lysates resolved the 2-5A activity into both 100-kD and 30-kD fractions. At 48 h after treatment with rIFN-alpha A, the activity of the 30-kD synthetase was approximately twofold greater than that of the 100-kD enzyme. In contrast, the activity of both 30- and 100-kD enzymes were equivalent 48 h after treatment with rIFN-gamma.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium binding sites in plasmodia of Physarum polycephalum as revealed by the pyroantimonate technique

Plasmodia of the acellular slime mold, Physarum polycephalum, were treated with an osmium tetroxide fixative containing potassium pyroantimonate to precipitate calcium and thereby localize calcium binding sites and sites of increased calcium concentration. Dense calcium pyroantimonate precipitates were detected within the nucleoli. The distribution of these precipitates during interphase and mitosis coincides with the distribution of the unique minichromosomes in Physarum, i.e., the numerous short pieces of extrachromosomal nucleolar chromatin containing segments of amplified DNA coding for ribosomal RNA. Calcium pyroantimonate precipitates were present as frequent dense granules in the mitochondrial matrix and as fine precipitates in the mitochondrial nucleoid. Large calcium-containing precipitates were seen within cytoplasmic vacuoles, confirming reports by others. In addition, we have identified calcium binding sites along the cytoplasmic surface of the plasma membrane. The distribution of calcium within the plasmodium is discussed in relation to the assembly of the mitotic spindle and the regulation of cell motility.

Macrophage mediated damage to rat lenses in culture: a possible model for uveitis-associated cataract

Rat lenses incubated in the presence of "activated" murine peritoneal macrophages are markedly impaired in their ability to accumulate certain radio-labeled compounds from the culture medium whereas incubation with resident macrophages has no such effect. The damage to the lens can be prevented in part by addition of certain antioxidants to the culture medium. The results suggest that mediators released by activated macrophages may be involved in initiation of the cataracts associated with chronic ocular inflammation.