Glass-clad single-crystal germanium optical fiber

Long lengths (250 meters) of a flexible 150 microm diameter glass-clad optical fiber containing a 15 microm diameter crystalline and phase-pure germanium core was fabricated using conventional optical fiber draw techniques. X-ray diffraction and spontaneous Raman scattering measurements showed the core to be very highly crystalline germanium with no observed secondary phases. Elemental analysis confirmed a very well-defined core-clad interface with a step-profile in composition and nominally 4 weight-percent oxygen having diffused into the germanium core from the glass cladding. For this proof-of-concept fiber, polycrystalline n-type germanium of unknown dopant concentration was used. The measured infrared transparency of the starting material was poor and, as a likely outcome, the attenuation of the resultant fiber was too high to be measured. However, the larger Raman cross-section, infrared and terahertz transparency of germanium over silicon should make these fibers of significant value for fiber-based mid- to long-wave infrared and terahertz waveguides and Raman-shifted infrared light sources once high-purity, high-resistivity germanium is employed.

Fgfr mRNA isoforms in craniofacial bone development

Mutations in genes encoding for fibroblast growth factor receptors (FGFRs) have been identified as causes of both chondrodysplasias and craniosynostoses, both of which cause abnormalities in the growth and development of the craniofacial region. FGFRs form mRNA splicing isoforms, each with distinct ligand binding specificity and tissue distribution. These confer specific biological functions on these isoforms. Although it is known that FGFRs are expressed at numerous locations during early mouse development, including the craniofacial area, relatively little is known about the expression of the splicing isoforms during craniofacial bone development. To address this, we have performed a detailed survey to detect these genes in the developing mouse craniofacial region. We have analyzed the developing mouse mandible, calvaria, and cranial base, in particular the spheno-occipital synchondrosis, a key centre of craniofacial growth. Fgfr1c was detected weakly in osteoblastic cells in both the developing calvarial and mandibular bones. Fgfr3b and Fgfr3c were found chiefly in proliferating chondrocytes of the cranial base synchondroses and the mandibular condyle. Fgfr2b transcripts were most notably detected in the perichondria of the mandibular condyle and the cranial base. Fgfr2c transcripts were detected with high intensity in differentiating osteoblasts at the sutural osteogenic fronts of the calvarial bones. In addition, Fgfr2c was also expressed in the perichondria of the mandibular condyle and the cranial base. These expression patterns suggest both differing and similar functions for -b and -c isoforms. The former is exemplified by Fgfr1 transcripts, which show distinct differences in their distribution, being mutually exclusive. Similar functions are suggested by the overlapping expression patterns of the -b and -c isoforms of both Fgfr2 and Fgfr3. Fgfr4 transcripts were found in developing muscles. These data help to explain the disturbances in craniofacial growth exhibited by both patients and the growing number of transgenic mice carrying mutations in genes encoding FGFRs/Fgfrs.

Hormone-dependent, CARM1-directed, arginine-specific methylation of histone H3 on a steroid-regulated promoter

Activation of gene transcription involves chromatin remodeling by coactivator proteins that are recruited by DNA-bound transcription factors. Local modification of chromatin structure at specific gene promoters by ATP-dependent processes and by posttranslational modifications of histone N-terminal tails provides access to RNA polymerase II and its accompanying transcription initiation complex. While the roles of lysine acetylation, serine phosphorylation, and lysine methylation of histones in chromatin remodeling are beginning to emerge, low levels of arginine methylation of histones have only recently been documented, and its physiological role is unknown. The coactivator CARM1 methylates histone H3 at Arg17 and Arg26 in vitro and cooperates synergistically with p160-type coactivators (e.g., GRIP1, SRC-1, ACTR) and coactivators with histone acetyltransferase activity (e.g., p300, CBP) to enhance gene activation by steroid and nuclear hormone receptors (NR) in transient transfection assays. In the current study, CARM1 cooperated with GRIP1 to enhance steroid hormone-dependent activation of stably integrated mouse mammary tumor virus (MMTV) promoters, and this coactivator function required the methyltransferase activity of CARM1. Chromatin immunoprecipitation assays and immunofluorescence studies indicated that CARM1 and the CARM1-methylated form of histone H3 specifically associated with a large tandem array of MMTV promoters in a hormone-dependent manner. Thus, arginine-specific histone methylation by CARM1 is an important part of the transcriptional activation process.

Neuropsychological performance in asymptomatic HIV infection

This study compared 74 human immunodeficiency virus (HIV)-negative and 131 HIV-positive asymptomatic homosexual or bisexual men on an extensive neuropsychological test battery. HIV-positive subjects' performance was significantly worse on verbal memory and psychomotor skills. The prevalence of mild but persistent neurobehavioral impairment in the HIV-positive group was approximately twice that in HIV-negative patients, consistently across several criteria for impairment. There was evidence that degree of neuropsychological impairment was related to patients' perceptions of dysfunction in daily life. Findings were not related to degree of depression or to medication effects. These data suggest that approximately 10% to 20% of HIV-positive asymptomatic men suffer mild neuropsychological impairment that influences their daily lives.

Randomized controlled trial of IVIg in untreated chronic inflammatory demyelinating polyradiculoneuropathy

OBJECTIVE

To determine the efficacy of IV immunoglobulin (IVIg) given patients with untreated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).

METHODS

A randomized, double-blind, multicenter, investigator-initiated study compared IVIg (Aventis Behring LLC, King of Prussia, PA) with placebo (5% albumin). On days 1, 2, and 21, IVIg (1 g/kg) or placebo was given. The primary outcome measure was the change in muscle strength from baseline to day 42, using the average muscle score (AMS). Secondary outcome measures included change from baseline AMS at days 10 and 21, the Hughes' functional disability scale, forced vital capacity (FVC), and nerve conduction studies (NCS) of four motor nerves (median, ulnar, peroneal, and tibial).

RESULTS

The patients (n = 33) were randomized. Of these, 30 (14 women, 16 men, aged 54 +/- 20 years, range 13 to 82) received IVIg and 23 were given placebo (12 women, 11 men, aged 50 +/- 18 years, range 23 to 73). Baseline AMS values of the groups were similar (IVIg 7.06 +/- 1.31 versus placebo 7.28 +/- 1.18, p = 0.53). There were two dropouts in placebo group and one in the IVIg group. Mean AMS improved at day 42 comparing IVIg with placebo (0.63 versus -0.1, p = 0.006). Improved strength was seen by day 10. The placebo group lost strength over this same interval. In the IVIg, 11 subjects improved by the functional disability scale; none worsened. This differed (p = 0.019) from those in the placebo-treated group (two improved, two got worse, remainder unchanged). Forced vital capacity did not improve with IVIg treatment. IVIg improved ulnar motor distal latency (p = 0.005), tibial distal compound muscle amplitude (p = 0.003), and peroneal nerve conduction velocity (p = 0.03).

CONCLUSIONS

IVIg improves strength in patients with untreated CIDP by day 10 with continued benefit through day 42; more than one third improve by at least a functional grade on a disability scale. This study provides data supporting IVIg as the initial treatment for CIDP.

Influence of human immunodeficiency virus infection on pelvic inflammatory disease

OBJECTIVE

To examine the influence of human immunodeficiency virus (HIV) infection on clinical and microbiologic characteristics of pelvic inflammatory disease (PID).

METHODS

Forty-four HIV-infected women and 163 HIV noninfected women diagnosed with PID by standard case definition were evaluated by using clinical severity scores, transabdominal sonograms, and endometrial biopsies. After testing for bacterial infections, patients were prescribed antibiotics as recommended by the Centers for Disease Control and Prevention (CDC).

RESULTS

Symptoms of PID and analgesic use before enrollment did not differ by HIV serostatus. More HIV-infected women had received antibiotics before enrollment (40.9% versus 27.2%, P =.08), a factor associated with milder signs regardless of serostatus. More HIV-infected women had sonographically diagnosed adnexal masses at enrollment (45.8% versus 27.1%, P =.08), a difference that yielded higher median severity scores (17.5 of 42 points versus 15 of 42 points, P =.07). However, those differences were not significant at the P <.05 level. Mycoplasma (50% versus 22%, P <.05) and streptococcus species (34% versus 17%, P <.05) were isolated more commonly from biopsies of HIV-infected women. Within 30 days after enrollment, HIV-infected women generally responded as well to therapy as HIV-noninfected women did, regardless of initial CD4 T-lymphocyte percentage.

CONCLUSION

Among women with acute PID, HIV infection was associated with more sonographically diagnosed adnexal masses. Clinical response to CDC-recommended antibiotics did not differ appreciably by serostatus. Mycoplasmas and streptococci were isolated more commonly from HIV-infected women, but those organisms also might be associated with PID in immunocompetent women.