Movement characteristics and power output of guinea-pig and hamster spermatozoa in relation to activation

Spermatozoa were collected from the cauda epididymidis of golden hamsters and guinea-pigs, and the acrosome reaction was induced in vitro. Movement characteristics of the spermatozoa were assessed with high-speed cinemicrography. Before the initiation of the acrosome reaction (preactivated spermatozoa), sperm movement in both species was characterized by progressive swimming by regular flagellar waves of moderate amplitude and relative high frequency. After the acrosome reaction (activated spermatozoa), sperm movement in both species was not progressive, and was characterized by whiplash-like flagellar undulations of significantly (P less than 0.05) higher amplitude and lower frequency. Calculation of the hydrodynamic power output by a new theory indicated that no significant change occurred after activation.     

Studies on the biological activities of actinomycins Z1 and Z5

The biological activities of actinomycins Z₁, Z₅, and IV (D) were compared. No consistent pattern was observed between the in vitro and in vivo results. Inhibition of E. coli DNA-dependent RNA polymerase in vitro followed the sequence IV > Z₁ > Z₅; however, for inhibition of RNA synthesis in B. subtilis and in HeLa cells the sequence was IV > Z₅ > Z₁ and the latter relationship was seen in the antimicrobial activity also. Physicochemical data did not agree with any of these findings. Difference spectra obtained with B. subtilis and M. lysodeikticus DNA followed the sequence Z₁ > IV > Z₅, while the relative thermal denaturation profiles were the exact opposite, Z₅ > IV > Z₁. These physicochemical criteria appear to be less reliable quantitative guides to biological activity. The relative ineffectiveness of actinomycin Z₁in vivo is probably the result of permeability differences associated with the presence of an hydroxylated proline residue (3-hydroxy-4-oxo-5-methylproline).     

Chronic Kidney Disease in Non-Diabetic Older Adults: Associated Roles of the Metabolic Syndrome,Inflammation, and Insulin Resistance

Background

The aims of the study were to examine the association between CKD and the metabolic syndrome (MetS) and its components in older adults. We also explored two possible pathways linking the metabolic syndrome with CKD: inflammation as measured by high sensitivity C-Reactive Protein (hsCRP) and insulin resistance as measured by HOMA-IR.

Methods

Community-dwelling non-diabetic 70+ adults from the Einstein Aging Study participated in the study. We defined CKD as eGFR below 60mL/min/1.73m². MetS was defined according to recent guidelines from the National Cholesterol Education Program. Binary logistic regressions were used to assess the association between the metabolic syndrome, its components and CKD with adjustments for demographics, HOMA-IR and hsCRP.

Results

Of 616 participants (mean age = 79.3 years, 65.5% female), 25% had MetS and 26.5% had CKD. Participants with CKD had a significantly higher prevalence of the MetS than individuals without CKD (34.4% vs. 24.3%). Binary logistic regression models showed that CKD was associated with MetS (OR = 1.72, 95%CI = 1.13–2.61). The association was unaltered by adjustment for hsCRP but altered by adjustment for HOMA-IR. As the number of MetS components increased the relative odds of CKD also increased. None of the individual components was independently associated with CKD.

Conclusion

MetS is associated with CKD in non-diabetic older adults. Results showed that as the number of MetS components increased so did the odds for CKD. HOMA-IR seems to be in the casual pathway linking MetS to CKD.     

Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains

Background

Although cutaneous ulcers (CU) in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU) and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin?

Methodology/Principal Findings

To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya) and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin.

Conclusions/Significance

These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions.