Ataxic sensory neuropathy and dorsal root ganglionitis associated with Sjögren's syndrome

Thirteen patients, 11 women and 2 men, developed sensory and autonomic neuronopathies in association with features of primary Sjögren's syndrome. In 11, Sjögren's syndrome had not been previously diagnosed at the time of neurological presentation. All had prominent loss of kinesthesia and proprioception. Pain and thermal sensibility were less severely affected. Most had evidence of autonomic insufficiency. In some this was severe, with Adie's pupils, fixed tachycardia, and orthostatic hypotension. The course ranged from an abrupt, devastating onset to indolent progression over years. Stabilization or functional improvement occurred in 6 patients, 2 of whom received no drug therapy. Sensory nerve conduction studies and examination of nerve biopsy specimens demonstrated a wide spectrum in the severity of loss of large myelinated fibers. The cutaneous nerves of 6 patients had perivascular mononuclear infiltrates without necrotizing arteritis. Examination of biopsy specimens of dorsal root ganglia in 3 patients revealed lymphocytic (T-cell) infiltration in the dorsal roots and ganglia, with focal clusters around neurons. In the more mildly affected ganglia, individual sensory neurons were undergoing degeneration. In the most advanced case, very few neurons remained. The possibility of Sjögren's syndrome should be considered in patients, especially women, who develop acute, subacute, or chronic sensory and autonomic neuropathies, with ataxia and kinesthetic loss.

Sequence analysis of the wheat mitochondrial atp6 gene reveals a fused upstream reading frame and markedly divergent N termini among plant ATP6 proteins

The nucleotide sequence of the wheat mitochondrial gene for subunit 6 (atp6) of the F1F0 ATPase complex has been determined. Unlike bacterial, chloroplast or animal/fungal mitochondrial atp6 counterparts, which encode proteins of about 230-270 amino acids, the wheat mitochondrial atp6 homologue comprises the latter part of an open reading frame (ORF) of 386 codons. The ATP6 protein may therefore by synthesized with a long N-terminal presequence. This is supported by the finding that the ORF is preceded by a conserved sequence block closely related to ones preceding several other actively transcribed wheat mitochondrial protein-coding genes. The fused upstream ORF is similar in length, but unrelated in sequence, to those preceding the maize and tobacco mitochondrial atp6 genes. In wheat, the atp6 gene is located on a recombinationally active repeated DNA element, whose length of 1.4 kb corresponds approximately to that of the atp6 mRNA. A comparison of the wheat and maize ATP6 sequences reveals unexpectedly high divergence in the region corresponding to the mature N-terminal domain and may reflect mitochondrial DNA rearrangements during atp6 gene evolution in monocotyledonous plants.

Performance of amblyopic children on printed contrast sensitivity test charts

Forty consecutive amblyopic patients between the ages of 3 and 12 years attending the Orthoptic Clinic for assessment and treatment were tested on the AO Contrast Sensitivity System [Arden grating test (AGT)] and the VISTECH Contrast Sensitivity Charts. Recordings were unsuccessful in more than 50% of these patients on both test systems. Of those who could successfully complete the AGT, false negative results were noted in 62.5% of the amblyopic eyes and false positive results were found in 25% of the normal fellow eyes. On the near VISTECH chart, all normal and amblyopic eyes produced results that were outside the specified limit of normality. On the distance VISTECH chart, 25% of the normal fellow eyes gave false positive results and 25% of the amblyopic eyes gave false negative results. From these findings, it is doubtful whether either test system has a role in the routine clinical assessment of amblyopia.

Axillary 5 alpha-androst-16-en-3-one in men and women: relationships with olfactory acuity to odorous 16-androstenes

Axillary 5 alpha-androst-16-en-3-one (5 alpha-androstenone) levels were found to be significantly higher in men than in women but do not vary between left and right axillae, are not related to age, handedness or degree of hirsutism (in women) nor to anosmia to this steroid. In men (but not in women), levels are related linearly to axillary cholesterol concentrations but not to squalene. Olfactory thresholds for 5 alpha-androstenone varied widely, the lowest recorded being 0.2 ppb, but there was no difference in thresholds between men and women. Women (70%) found the smell 'repellant' but anosmia did not differ greatly between men and women (9-20%). Anosmia to the smell of 5 alpha-androst-16-en-3 alpha-ol was most marked in women (90%) rather than in men (45%). Axillary 5 alpha-androstenone values were generally consistent with the 'musky' or 'strong' smells of male axillary extracts, compared with the 'sweet' smell of those from female subjects.

Estimation of the odorous steroid, 5 alpha-androst-16-en-3-one, in human saliva

The concentration of the urine-smelling steroid, 5 alpha-androst-16-en-3-one, has been measured by radioimmunoassay in the saliva of 9 men and 4 women. The lower limit of detection was estimated to be 0.725 nmoles/l. In six of the men the range of concentrations of the odorous steroid was 0.8-1.8 nmoles/l saliva (3 men had less than the estimated lower limit of detection). In only one of the women studied could the 5 alpha-androst-16-en-3-one be measured (0.83 nmoles/l) in the saliva.

Requirements for antiribosomal activity of pokeweed antiviral protein

It has been known for some time that pokeweed antiviral protein acts by enzymatically inhibiting protein synthesis on eucaryotic ribosome systems. The site of this action is known to be the ribosome itself. In this paper we show that the pokeweed antiviral protein reaction against ribosomes is a strong function of salt concentrations, where 160 mM K+ and 3 mM Mg2+ retards the reaction, while 20 mM K+ and 2 mM Mg2+ allows maximum reaction rate. It is also shown, however, that an unidentified protein in the postribosomal supernatant solution, together with ATP, allows the ribosome to be attacked even in the presence of high salt. Kinetic analysis of the antiviral protein reaction has been carried out under both sets of conditions, and reveals that the turnover number for the enzyme is about 300-400 mol/mol per min. in each case. The Km for ribosomes is 1 microM in the presence of low salt and 0.2 microM at higher salt in the presence of postribosomal supernatant factors plus ATP. The antiviral protein reaction is also shown to be pH dependent and is controlled by a residue with pKa value of approx. 7.0, apparently a histidine. Stoichiometric reaction of the enzyme with iodoacetamide results in a significant loss of antiribosomal activity.

Axillary 5 alpha-androst-16-en-3-one, cholesterol and squalene in men; preliminary evidence for 5 alpha-androst-16-en-3-one being a product of bacterial action

Twenty-four hour axillary levels of the odorous steroid 5 alpha-androst-16-en-3-one, have been measured in six men by radioimmunoassay. Initially, no control of bacterial activity was made and conditions attempting a normal axillary environment were maintained. The level of 5 alpha-androst-16-en-3-one was significantly higher (P = 0.028) in one axilla ("superior") than the other ("inferior") and levels showed considerable variation both between and within individuals. This difference between axillae was also observed for cholesterol (P = 0.0013) but not for squalene (P = 0.18). This suggests that the presence of 5 alpha-androst-16-en-3-one in the axilla does not correlate with sebum secretion. The effect of a general germicidal agent was tested by shaving and applying Povidone-iodine to the "superior" axilla whilst treating the "inferior" axilla as a control. A highly significant drop in the level of 5 alpha-androst-16-en-one in the "superior" axilla below that in the control axilla was obtained (P = 0.000014, double tailed, as calculated using the Fisher Exact test). Squalene and cholesterol were measured in an attempt to monitor glandular activity and their levels were not significantly affected by Povidone-iodine. It is likely, therefore, that the production of 5 alpha-androst-16-en-3-one is from metabolism of a percursor in the axillae by skin micro-organisms.

DNA methylation affecting the expression of murine leukemia proviruses

The endogenous, vertically transmitted proviral DNAs of the ecotropic murine leukemia virus in AKR embryo fibroblasts were found to be hypermethylated relative to exogenous AKR murine leukemia virus proviral DNAs acquired by infection of the same cells. The hypermethylated state of the endogenous AKR murine leukemia virus proviruses in these cells correlated with the failure to express AKR murine leukemia virus and the lack of infectivity of cellular DNA. Induction of the endogenous AKR murine leukemia virus proviruses with the methylation antagonist 5-azacytidine suggested a causal connection between DNA methylation and provirus expression. Also found to be relatively hypermethylated and noninfectious were three of six Moloney murine leukemia virus proviral DNAs in an unusual clone of infected rat cells. Recombinant DNA clones which derived from a methylated, noninfectious Moloney provirus of this cell line were found to be highly active upon transfection, suggesting that a potentially active proviral genome can be rendered inactive by cellular DNA methylation. In contrast, in vitro methylation with the bacterial methylases MHpaII and MHhaI only slightly reduced the infectivity of the biologically active cloned proviral DNA. Recombinant DNA clones which derived from a second Moloney provirus of this cell line were noninfectious. An in vitro recombination method was utilized in mapping studies to show that this lack of infectivity was governed by mechanisms other than methylation.

Evidence for the Asiatic origin of endogenous AKR-type murine leukemia proviruses

A restriction endonuclease cleavage map of the genome of AKV, the endogenous, ecotropic leukemia virus of AKR mice, has been derived. By using this map and analyzing DNA from congenic mice, we have defined four DNA fragments diagnostic for AKV proviruses. Analysis of DNAs from 10 strains of American laboratory mice revealed that all strains carrying inducible, ecotropic murine leukemia viruses yielded DNAs which contained the four DNA fragments diagnostic for AKV. Virus-negative strains lacked these fragments in their DNA. Screening DNA from 23 additional mice revealed that, among these mice, only mice from Asia gave rise to the DNA fragments diagnostic of an AKV provirus. We conclude that all of the endogenous ecotropic murine leukemia proviruses in American laboratory mice are closely related since they share a common set of restriction endonuclease cleavage sites. These proviruses appear to derive from the East Asian ancestors of these mouse strains. Analysis of DNA from six selected mice with an additional restriction endonuclease showed that greater than 97% of the nucleotide sequences in each provirus are contigous and that these endogenous proviruses are indistinguishable from proviruses introduced by exogenous infection.

Identification of DNA fragments carrying ecotropic proviruses of AKR mice

The proviruses of the N-tropic, ecotropic virus (AKV) of AKR mice (Akv-1, Akv-2) have been studied by the Southern gel--filter transfer technique. These proviruses can be detected by cleavage of cell DNA by BamHI endonuclease, which yields characteristic subgenomic DNA fragments upon cleavage of this type of provirus. Proviruses integrated into different sites in the mouse genome can be resolved with EcoRI endonuclease, which does not cleave the AKV proviruses. Use of congenic and backcrossed mice and a radioactive DNA probe enriched for AKV sequences has allowed identification of the EcoRI fragments carrying the proviruses of the genetically defined Akv-1 and Akv-2 loci. Novel proviruses introduced by superinfection of cultured AKR cells with AKV and present in leukemic cells from AKR mice have also been identified. Comparison of substrains of AKR mice indicates some heterogeneity in their spectra of proviruses.