Analysis of the effects of oxygen supply and demand on hypoxic fraction in tumors.

The extent of hypoxic regions in a tumor tissue depends on the arrangement, blood flow rate and blood oxygen content of microvessels, and on the tissue's oxygen consumption rate. Here, the effects of blood flow rate, blood oxygen content and oxygen consumption on hypoxic fraction are simulated theoretically, for a region whose microvascular geometry was derived from observations of a transplanted mammary andenocarcinoma (R3230AC) in a rat dorsal skin flap preparation. In the control state, arterial PO2 is 100 mmHg, consumption rate is 2.

Risks and behaviour in patients requesting HIV tests.

A prospective survey to assess reasons for requesting HIV tests, perceived HIV risk and sexual behaviour in genitourinary medicine clinic attenders was carried out. Overall 123 (38.6%) were concerned about casual sexual contacts.

Mortality and survival trends in patients with AIDS in north east England from 1984-1992.

Objective: to study trends in mortality and survival in patients with AIDS attending an ID unit.

Method: retrospective analysis of patients developing an AIDS-defining illness between April 1984, and November 1992. Survival was analysed by calculation of survival product-limit.

Comparison of radiovisiography with radiographic film in root length determination.

Radiovisiography is a digital intraoral radiographic imaging system requiring a substantial reduction of radiation dosage to the patient over film. For Radiovisiography to replace film, it must be shown to be as efficacious. In this study, a technique of obtaining Radiovisiography and D-speed film images from the same X-ray beam was developed with the use of rare-earth filters.

Cross-talk among ROR alpha 1 and the Rev-erb family of orphan nuclear receptors.

We have cloned Rev-erb beta, a novel isoform of the Rev-erb alpha orphan nuclear receptor. The DNA binding domains of Rev-erb alpha and beta are highly related to each other and to the retinoic acid related orphan receptor (ROR)/RZR subfamily of nuclear receptors. Indeed, we find that all three receptors bind as monomers to the sequence AATGT-AGGTCA.

Giant cell arteritis--A cause of pyrexia of unknown origin.

Giant cell arteritis may present atypically with symptoms of malaise, anorexia, weight loss and fever that could lead to diagnostic difficulties. We describe two cases which the prominent initial feature was protracted pyrexia. Clinicians should seriously consider temporal artery biopsy in such cases.

Differential expression and activation of a family of murine peroxisome proliferator-activated receptors.

To gain insight into the function of peroxisome proliferator-activated receptor (PPAR) isoforms in mammals, we have cloned and characterized two PPAR alpha-related cDNAs (designated PPAR gamma and -delta, respectively) from mouse. The three PPAR isoforms display widely divergent patterns of expression during embryogenesis and in the adult. Surprisingly, PPAR gamma and -delta are not activated by pirinixic acid (Wy 14,643), a potent peroxisome proliferator and activator of PPAR alpha.

Determination of local oxygen consumption rates in tumors.

At any location in a respiring tissue, partial pressure of oxygen (PO2) is influenced by the local oxygen consumption rate. Consumption rates in vascular tumor tissues have previously been estimated for macroscopic regions. Using oxygen electrodes, we measured PO2 profiles across microregions (87 microns to 286 microns wide) of tumors (R3230AC mammary adenocarcinoma) in a rat dorsal skin flap preparation and mapped adjacent microvessels.

Intravenous azithromycin as salvage therapy in a patient with Legionnaire's disease.

A patient with proven Legionnaire's disease is described whose clinical condition improved with intravenous azithromycin after failure to respond to treatment with erythromycin and rifampicin.

Non-S-layer glycoproteins in eubacteria.

Glycoproteins are proving to be quite common in prokaryotes. Those in S-layers are the best understood in terms of structure. Numerous eubacteria produce non-S-layer glycoproteins about which relatively little is known.

Chromosomal localization of the human retinoid X receptors.

The recently described retinoid X receptors (RXRs) respond to the novel retinoid 9-cis-retinoic acid and also serve as heterodimeric partners for the vitamin D, thyroid hormone, and retinoic acid receptors (VDR, TR, and RAR, respectively). In this work, we report high-resolution localization of the human RXR genes within cytogenetic bands and also within a standard reference map of cosmid DNA markers on human chromosomes. We have determined the location of the human RXR genes by pairwise hybridization of the RXR cosmids and reference markers, using fluorescence in situ hybridization.

Immunological relationships among group I and group V allergens from grass pollen.

Specific IgE antibodies have been affinity-purified from recombinant grass pollen allergens, and used to identify isoforms of the two major allergens of rye-grass pollen, Lol p I and Lol p V and cross-reactive allergens in other grasses. Lol p I-specific IgE (affinity-purified from the recombinant protein expressed by clone 13R which encodes amino acids 96-240 of Lol p I) identified four isoforms of the allergen. The same probe recognized cross-reactive epitopes in pollen proteins from 14 out of 16 grasses.

Isoform-specific amino-terminal domains dictate DNA-binding properties of ROR alpha, a novel family of orphan hormone nuclear receptors.

Three isoforms of a novel member of the steroid hormone nuclear receptor superfamily related to the retinoic acid receptors have been identified. The three isoforms, referred to as ROR alpha 1, ROR alpha 2, and ROR alpha 3, share common DNA- and putative ligand-binding domains but are characterized by distinct amino-terminal domains generated by alternative RNA processing. An exon encoding a functionally important subregion of the amino-terminal domain of the ROR alpha 2 isoform resides on the opposite strand of a cytochrome c-processed pseudogene.

Streptomyces lividans glycosylates the linker region of a beta-1,4-glycanase from Cellulomonas fimi.

The beta-1,4-glycanase Cex of the gram-positive bacterium Cellulomonas fimi is a glycoprotein comprising a C-terminal cellulose-binding domain connected to an N-terminal catalytic domain by a linker containing only prolyl and threonyl (PT) residues. Cex is also glycosylated by Streptomyces lividans. The glycosylation of Cex produced in both C.

Cloning of a cDNA encoding a group-V (group-IX) allergen isoform from rye-grass pollen that demonstrates specific antigenic immunoreactivity.

We have isolated and characterized the cDNA clone, 19R, that encodes an isoform of a major rye-grass pollen allergen, Lol p V [previously referred to as Lol p 1b; Singh et al., Proc. Natl.

The cellulose-binding domain (CBD(Cex)) of an exoglucanase from Cellulomonas fimi: production in Escherichia coli and characterization of the polypeptide.

The gene fragment encoding the cellulose-binding domain (CBD) of an exoglucanase (Cex) from Cellulomonas fimi was subcloned and expressed in Escherichia coli. Transcription from the lac promoter coupled with translation from a consensus prokaryotic ribosome binding site led to the production of large quantities of CBD(Cex) (up to 25% total soluble cell protein). The polypeptide leaked into the culture supernatant (up to 50 mg .

Tonic vergence, age and clinical presbyopia.

The relative contribution of tonic vergence to the maximum near vergence response as a function of age and the development of presbyopia has received little attention. Tonic vergence position was measured subjectively in a group of 50 subjects between 20 and 68 years of age. While there was no progressive trend with age, tonic vergence did exhibit a small but consistent convergent increase after 40 years of age.

The role of aerosol pentamidine prophylaxis.

Pneumocystis carinii pneumonia (PCP) is the most frequent opportunistic infection in patients with AIDS, occurring in 80% and recurring in 50% of patients within 12 months of the first episode. Prophylaxis for PCP is recommended if the CD4+ cell count is < 200 x 10(6)/l or 20% of the total lymphocyte count, or after an episode of PCP. The most effective prophylactic agent currently is trimethoprim-sulphamethoxazole and should be the drug of choice but alternatives such as aerosol pentamidine are being increasingly used for patients who cannot tolerate this combination or other oral preparations.

Static accommodation in congenital nystagmus.

Purpose: To conduct a comparative study of static accommodative function between individuals with normal vision (n = 10) and patients with congenital nystagmus (n = 12).

Methods: The component contribution to monocular steady-state accommodation (slope of the accommodative stimulus/response function, accommodative controller gain, tonic accommodation, and depth-of-focus) was assessed subjectively using a Hartinger coincidence-optometer, except for depth-of-focus, which was determined psychophysically.

Results: The group mean slope for the patients with nystagmus was not significantly different from that found in the normal subjects.

Bronchial responsiveness in AIDS patients with Pneumocystis carinii pneumonia.

Objective: To study bronchial responsiveness to inhaled histamine among HIV-infected patients.

Design: A prospective study in a regional infectious diseases unit.

Methods: Three groups of patients were studied.