Re-routing of Sugar Catabolism Provides a Better Insight Into Fungal Flexibility in Using Plant Biomass-Derived Monomers as Substrates

The filamentous ascomycete Aspergillus niger has received increasing interest as a cell factory, being able to efficiently degrade plant cell wall polysaccharides as well as having an extensive metabolism to convert the released monosaccharides into value added compounds. The pentoses D-xylose and L-arabinose are the most abundant monosaccharides in plant biomass after the hexose D-glucose, being major constituents of xylan, pectin and xyloglucan. In this study, the influence of selected pentose catabolic pathway (PCP) deletion strains on growth on plant biomass and re-routing of sugar catabolism was addressed to gain a better understanding of the flexibility of this fungus in using plant biomass-derived monomers. The transcriptome, metabolome and proteome response of three PCP mutant strains, ΔlarAΔxyrAΔxyrB, ΔladAΔxdhAΔsdhA and ΔxkiA, grown on wheat bran (WB) and sugar beet pulp (SBP), was evaluated. Our results showed that despite the absolute impact of these PCP mutations on pure pentose sugars, they are not as critical for growth of A. niger on more complex biomass substrates, such as WB and SBP. However, significant phenotypic variation was observed between the two biomass substrates, but also between the different PCP mutants. This shows that the high sugar heterogeneity of these substrates in combination with the high complexity and adaptability of the fungal sugar metabolism allow for activation of alternative strategies to support growth.

Altered clinical presentation of early syphilis in patients with human immunodeficiency virus infection

OBJECTIVES

To compare clinical presentations of patients with early syphilis who did or did not have human immunodeficiency virus (HIV) infection.

DESIGN

Case-control study.

SETTING

The sexually transmitted diseases clinics of the Baltimore City Health Department.

PATIENTS

Patients with newly diagnosed primary, secondary, or early latent syphilis who had voluntary HIV testing from January 1990 to November 1991.

MEASUREMENTS

Data on sexual history, risk behaviors, and physical findings (before knowledge of HIV or syphilis serologic test results) were extracted from clinical records. Diagnoses of syphilis were confirmed by reactive syphilis serologic tests. Rapid plasma reagin titers reported to the disease registry of the Baltimore City Health Department were abstracted to determine therapeutic response. Patients positive for HIV who returned for follow-up had further counseling, staging, and CD4 lymphocyte testing.

RESULTS

Data were available on 309 of 527 patients with early syphilis: 108 patients with primary syphilis, 116 with secondary syphilis, and 85 with early latent syphilis. Seventy (23%) patients had concurrent HIV infection. Patients with HIV infection presented more often with secondary syphilis than did patients with syphilis who were HIV seronegative (53% [37 of 70] compared with 33% [79 of 239]; P = 0.01). The same was true for heterosexual men with HIV infection (46% [16 of 35]) compared with heterosexual men without infection (25% [35 of 142]; P < 0.03). Among those who denied intravenous drug use, 59% (22 of 37) of patients with HIV infection presented with secondary syphilis compared with 33% (65 of 198) of patients without infection (P < 0.01). Among patients with first episodes of syphilis, patients positive for HIV who had secondary syphilis were more likely to present with persistent chancres (43% [9 of 21] compared with 15% [11 of 72]; P = 0.01). The rate of decline in the rapid plasma reagin titers during a 12-month period after treatment did not differ between patients with and without HIV infection (P = 0.15).

CONCLUSIONS

The clinical presentation of syphilis in patients with HIV infection differs from that of patients without HIV infection in that patients with HIV infection present more often in the secondary stage and those with secondary syphilis are more likely to have chancres.

Assessing violent offending in serious juvenile offenders

The convergent validity of the two most frequently used methods for assessing violent offending in juveniles (i.e., self-reports and arrests) was evaluated. Participants were 87 serious juvenile offenders and their maternal figures, primarily from disadvantaged families. Validation measures tapped established behavioral, family, and peer correlates of delinquency. Results failed to support the ability of either arrests for violent crimes or self-reported violent offenses to index violent criminal behavior accurately. Several methodological features of the study support our hypothesis that the findings were not spurious. Procedural and conceptual implications of the findings are discussed.

CD4 lymphocyte concentrations in patients with newly identified HIV infection attending STD clinics. Potential impact on publicly funded health care resources

Since January 1990, human immunodeficiency virus (HIV)-infected patients attending two sexually transmitted disease clinics in Baltimore, Md, have been offered T-lymphocyte subset evaluations. From January through September, CD4+ lymphocyte concentrations were measured in 223 newly diagnosed HIV-infected patients; 50% had fewer than 500 CD4+ T cells and 12% had fewer than 200 CD4+ T cells per cubic millimeter. Most patients were asymptomatic, and, even among patients with fewer than 200 CD4+ T cells, 54% had no symptoms or signs suggestive of advanced HIV infection. Homosexually active men had significantly lower mean CD4+ lymphocyte concentrations than intravenous drug users. Given the substantial numbers of patients with CD4+ concentrations that qualified them for zidovudine therapy, we also assessed their mechanisms of paying for health care. Only 24% of HIV-infected patients had private insurance. Seventy-two percent of patients with fewer than 200 CD4+ T cells either had no insurance or relied on public assistance for health care. Thus, although 50% of asymptomatic individuals identified by routine voluntary HIV screening in an inner-city sexually transmitted disease clinic may benefit from therapy for their disease, 75% of those qualifying for presently recommended therapy either depend on publicly funded health care or have no means of payment for care.

Characteristics of patients with syphilis attending Baltimore STD clinics. Multiple high-risk subgroups and interactions with human immunodeficiency virus infection

Medical records of 341 patients with syphilis seen at a health department sexually transmitted disease clinic were reviewed to assess membership in high-risk subgroups and interactions with human immunodeficiency virus (HIV) infection. When compared with the entire clinic population, patients with syphilis tended to be older and were more likely to acknowledge intravenous drug use, more often had a history of syphilis, and, among men, were more often homosexually active. Half of the men with syphilis and one third of the women fell into one or more of these high-risk subgroups. Patients with syphilis were also more likely to test positive for HIV infection than other patients attending the clinic. Patients admitting to intravenous drug use, prior syphilis, or being homosexually active were significantly more likely to be HIV seropositive than patients without these characteristics, even though patients with these characteristics were significantly more likely to refuse HIV serologic testing. Although clinical stage of syphilis at presentation did not differ when patients with and without concurrent HIV infection were compared, geometric mean rapid plasma reagin titers were significantly higher in HIV-infected patients with secondary syphilis.

Syphilis in adults

This article reviews the clinical manifestations of syphilis, diagnostic tests that might help to diagnose accurately the disease, and current recommendations for therapy. The association of syphilis and human immunodeficiency virus infection raises additional questions related to transmission, diagnosis, and therapy of both diseases.

Use of electromyographic and skin-conductance biofeedback relaxation training of facilitate childbirth in primiparae

Matched groups of primigravid women received one of three antenatal training programmes: normal antenatal classes, normal classes plus electromyography biofeedback relaxation training, or normal classes plus skin-conductance biofeedback relaxation training. Myographic training was found to be effective within conventional antenatal constraints, whereas skin-conductance training was not. The women reported use of biofeedback training and related skills to be of some benefit during early labour. However, no difference between effectively trained electromyographic, ineffectively trained skin-conductance and control groups was found on labour and delivery performance measures.

The selection of patients with bronchogenic carcinoma for mediastinoscopy

The records of 112 patients treated at the Ochsner Foundation Hospital with the diagnosis of bronchogenic carcinoma were reviewed. A new concept for defining the location of central versus peripheral tumors is presented. Criteria important in selection of patients for whom mediastinoscopy is likely to be helpful are cell type, location (peripheral versus central), and radiographic evidence of mediastinal metastasis. The size of the tumor is not a useful criterion except possibly for squamous cell lesions. A high incidence of mediastinal metasis was found associated with central tumors (63 to 100 per cent) of all cell types and with peripheral lesions (63 per cent) of undifferentiated cell types. A relatively low incidence of mediastinal metasis was associated with peripheral asenocarcinomas or squamous cell tumors. We would, therefore, recommend mediastinoscopy for all patients with central lesions and those patients with peripheral lesions of an undifferentiated cell type. When correlated with radiographic findings, only 4.6 per cent of peripheral carcinomas of a differentiated cell type with a radiographically normal mediastinum were found to produce mediastinal metastases, and mediastinoscopy is not recommended. In patients with peripheral tumors of indeterminate cell type, a decision for mediastinoscopy may be influenced by other factors such as the operative risk of a thoracotomy and location of the primary tumor within the lung.