Analysis of metal incorporation during overexpression of Clostridium pasteurianum rubredoxin by electrospray FTICR mass spectrometry.

The rate of production of Clostridium pasteurianum rubredoxin overexpressed in Escherichia coli was examined by electrospray ionization-Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. Previous work had shown that this heterologous expression resulted in isolation of both iron-containing (FeRd) and zinc-containing (ZnRd) rubredoxins. In the present work, minimally processed cell lysates of E. coli were analyzed in order to monitor the production of FeRd and ZnRd. The sensitivity of the measurement favored FeRd relative to ZnRd, and this differential sensitivity was quantitated using previously separated and purified rubredoxins. A time course study indicated that ZnRd and FeRd are produced simultaneously during overexpression, but at different rates. The ratio of the concentration of ZnRd to FeRd increased in a linear fashion during 3 h following induction of overexpression. Since only FeRds have been reported from native bacteria and archaea, the data suggest that either Zn2+ is sequestered from rubredoxins during native biosynthesis or that ZnRds may have escaped detection in the native microorganisms. ESI-FTICR mass spectrometry is shown to be a useful tool for monitoring metal insertion during protein biosynthesis.

Skin wrinkling for the assessment of sympathetic function in the limbs.

BACKGROUND: Wrinkling of the skin of the palm and sole is considered to be dependent on the presence of intact sympathetic nervous activity. Loss of sympathetic integrity could be simply and usefully assessed by the absence of wrinkling. To test this hypothesis, the skin wrinkle test was compared with the starch-iodine sweat test and sympathetic skin response (SSR) in patients with abnormal sympathetic function. METHODS: The three tests were carried out in 34 patients (68 limbs) undergoing temporary or permanent disruption of the sympathetic chain to upper or lower limbs. Included in this group were six diabetics undergoing chemical or surgical sympathectomy, lumbar epidural infusions following vascular surgery, and patients for whom sympathectomy was being considered. Sensitivity and specificity analysis and predictive values of the wrinkling response and the starch-iodine test were related to the SSR as the standard. RESULTS: The wrinkle test showed a sensitivity of 97% and specificity of 95%, and bore good correlation to the SSR. The starch-iodine test showed sensitivity of 55% and specificity of 93%. A hypothesis for the mechanism of wrinkling based on the observations of the present study is proposed. CONCLUSION: The wrinkle test is a reliable test of sympathetic function, is inexpensive and is easy to perform at the bedside. The sweat gland myo-epithelial cells and absence of sebum could play an important role in the wrinkling response. It can be used to select patients who will benefit from sympathectomy, and can adequately evaluate sympathetic blockade.

Auditory and inspiratory gasp-evoked sympathetic skin response: age effects.

The sympathetic skin response (SSR) has been employed to assess peripheral neuropathy as an index of sympathetic sudomotor activity. A variety of stimuli can be used to elicit the SSR, but their relative ease of use and reliability have not been studied. In addition, the extent to which age affects the SSR remains unresolved. We compared two different stimuli, a sudden loud noise and an inspiratory gasp, whilst recording SSRs from the hand and foot. We also investigated the effects of age on SSR amplitude and latency in 58 healthy volunteers (ages 13-79). SSRs evoked by the auditory stimulus were recorded in all subjects, while gasp-induced SSRs were not elicited in two subjects. We found that SSRs evoked by the auditory stimulus had less inter- and intra-subject latency and waveform variability than the gasp-induced response. The increased latency variability associated with the inspiratory gasp technique was probably due to triggering errors. Our results confirmed that the amplitude of the SSR is extremely variable and appears to be affected by many factors. Auditory-evoked SSR latencies revealed a significant non-linear increase with age, while SSRs evoked by an inspiratory gasp did not demonstrate age dependence. We conclude that an auditory stimulus is superior to an inspiratory gasp in evoking SSRs, both in terms of consistent appearance and reduced latency variability. As the SSR latency increases significantly with age, this effect should be carefully considered when interpreting the response.

Isolated triceps weakness in exercise-induced radial neuropathy.

OBJECTIVE: We report a case of isolated triceps weakness resulting from radial neuropathy. PATIENT: A middle-aged healthy man, a keen athlete, developed acute weakness of the triceps brachii muscle due to radial neuropathy. No other radial nerve innervated muscles were involved. Triceps function completely recovered in six weeks clinically and electrophysiologically suggesting focal conduction block secondary to demyelination. DISCUSSION: Acute radial neuropathy after strenuous arm exercise resulting from a compression lesion with acute conduction block, has been previously described. However, all reported cases involved severe weakness of radial nerve innervated distal muscles with wrist drop, while isolated weakness of the triceps brachii muscle in radial neuropathy has never been previously described. CONCLUSIONS: We suggest that selective weakness in the triceps could be the sole manifestation of an exercise-related radial neuropathy. This particular type of radial neuropathy could be a variant of neuralgic amyotrophy.

CMAP dispersion, amplitude decay, and area decay in a normal population.

The aim of this investigation was to define the boundaries of compound motor action potential (CMAP) dispersion, amplitude decay, and area decay in a control population and determine their dependence on external variables such as age and interelectrode distance. Measurements were made from median, ulnar, and common peroneal motor nerves of 110 normal subjects of ages 15-90 years. Significant differences between nerves were found in mean values of each parameter. Dispersion and amplitude decay increased with the square of age in all three nerves, while area decay increased with age in the median nerve. Dispersion was the main cause of amplitude decay. Use of regression equations to predict dispersion and amplitude decay in each nerve significantly tightened confidence limits and should therefore increase the accuracy of these parameters in detecting demyelinating pathology in peripheral nerve.

High-dose intravenous human immunoglobulin in chronic inflammatory demyelinating polyneuropathy.

We treated nine consecutive patients with chronic inflammatory demyelinating polyneuropathy (CIDP) with high-dose intravenous human immunoglobulin (HIG), and clinical recovery rapidly followed. Disability that had persisted for months or years was often reversed in days. There were no major adverse reactions to HIG infusions.

Vaginal candidosis: relation between yeast counts and symptoms and clinical signs in non-pregnant women.

Of 277 non-pregnant women, 67 (24%) harboured Candida albicans in the genital tract. Of 56 women yielding C albicans who had no other infection diagnosed, 14 were symptomless and 10 had no clinical signs of vulval redness, vaginitis, or discharge. Symptoms and signs tended to be more severe in women with higher yeast counts. Of 22 women with moderate or severe symptoms (pruritus with or without discharge) and signs, 15 had yeast counts of more than 10(3) colony forming units (cfu)/ml, whereas six of nine women with no symptoms or signs had counts of fewer than 10(3) cfu/ml.

Evaluation of a new slide latex agglutination test for diagnosis of vaginal candidosis.

A new commercial slide latex particle agglutination test for rapid (2 min) diagnosis of vaginal candidosis was evaluated and compared with conventional methods. Of the 263 women studied, 63 (23.9%) had yeasts in the vagina. Clinical signs of vulvitis or vaginitis were seen in 23 women (8.8%) and 40 (15.2%) were harbouring yeasts without clinical signs. Yeast counts were generally higher in women with clinical signs of vaginal candidosis than in those without. The test was positive in 15 of the 23 women (65.2%) with clinical signs, the incidence of a positive test increasing in direct proportion to the amount of yeasts isolated. The test's sensitivity, specificity and predictive values were comparable to those of microscopy and culture. Being both rapid and simple to perform, this new test offers a useful alternative to conventional methods for the diagnosis of vaginal candidosis.

A modified mirror projection visual evoked potential stimulator for presenting patterns in different orientations.

Modifications to a standard mirror projection visual evoked potential stimulator are described to enable projection of patterns in varying orientations. The galvanometer-mirror assembly is mounted on an arm which can be rotated through 90 degrees. This enables patterns in any orientation to be deflected perpendicular to their axes.

Recurrent genital herpes suppressed by oral acyclovir: a multicentre double blind trial.

Eighty-eight of 111 patients with frequently recurring genital herpes attending five centres completed a randomized, double-blind, cross over trial with 200 mg oral acyclovir four times daily for 84 days before or after a similar course of placebo tablets. During the course of placebo 77 (88%) patients reported the development of lesions, four (5%) the development of symptoms and/or erythema but no further signs of a recurrence and seven (8%) remained entirely free of symptoms and signs. In contrast during acyclovir therapy only 11 (13%) patients reported lesions, a further 37 (42%) the development of symptoms and/or erythema only, while 40 (45%) patients remained entirely free of symptoms and signs. For each parameter the difference between active and placebo treatments was highly significant (P less than 0.001). Median times to recurrence after the end of both courses were similar. The drug was well tolerated and the findings indicate that continuous oral acyclovir therapy has a place in the management of frequent recurrences of genital herpes though the indications are not entirely clear. One possibility is the suppression of recurrence at times when it would be especially unwelcome such as during examinations or holidays.

The inability of dynamic tests of prolactin and TSH secretion to differentiate between tumorous and non-tumorous hyperprolactinemia.

Certain hyperprolactinemic patients have an obvious pituitary tumor while others with normal pituitary radiology may or may not harbor a pituitary microadenoma. A variety of biochemical tests have been proposed to distinguish between those with and those without pituitary tumors. The aims of this study were: firstly to examine these tests to assess their efficacy in differentiating between patients with radiologically-demonstrated pituitary tumors and normal controls; and secondly to establish if those hyperprolactinemic patients with normal radiology formed two distinct groups biochemically as might be expected if some did and some did not have tumors. The prolactin (PRL) and thyroid stimulating hormone (TSH) response to domperidone and the PRL response to TRH and insulin-induced hypoglycemia have thus been examined in hyperprolactinemic subjects with and without radiological evidence of an adenoma and in normal controls. The basal serum PRL was similar in patients with and without radiological evidence of a pituitary adenoma. The serum PRL response to all stimuli studied, expressed as a percentage of initial values, was blunted in patients with known pituitary tumors with total separation from values in control subjects. Results for patients with normal pituitary radiology were similar to those for patients with tumors with minimal overlap with controls. The peak TSH increment after domperidone was exaggerated in patients with known tumors, but overlap with control values was observed in 25%. In patients with normal radiology the peak TSH increment after domperidone was similarly increased but again overlap with control values occurred in 28%. Cluster analysis showed no evidence of two subgroups of response with in the hyperprolactinemic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Non-linear effects of age on nerve conduction in adults.

The effects of age on conduction and amplitude in median and ulnar (motor and sensory), superficial radial, sural and common peroneal (motor) nerves of adults were prospectively investigated. Four routinely recorded parameters, including conduction velocity, amplitude and duration, were considered for each sensory nerve and measurements of conduction velocity, terminal motor latency and amplitude were made for each motor nerve. The resulting 25 sets of data were analysed using both linear and quadratic regression. The three sets of terminal motor latency data showed no age dependence while in six other instances there was a linear relationship with age (three of these being motor amplitude). The remaining 16 sets of data were statistically best represented by quadratic analysis. The shapes of the paraboli were remarkably similar, reaching a maximum (conduction velocity and amplitude) or minimum (duration) value in the fourth decade and thereafter declining or rising respectively at an accelerating rate. With only one exception, quadratic curves of the same parameter were shown to be parallel. Tables of normal data which make accurate adjustments for the aging effect can be constructed from this analysis for use in routine clinical investigation.

Effect of an oral serotonin antagonist, ketanserin, on plasma ACTH concentrations in Nelson's syndrome.

A study was performed to see whether ketanserin, a serotonin antagonist, would reduce the raised concentrations of adrenocorticotrophic hormone (ACTH) in patients with Nelson's syndrome. Six patients who had undergone bilateral adrenalectomy for Cushing's disease and who had Nelson's syndrome were given ketanserin 40 mg twice daily and placebo, for at least two months each, in a double blind crossover study. Ketanserin had no effect on ACTH concentrations. In healthy people serotonin seems to have a stimulatory role in the regulation of ACTH secretion, and the effect of ketanserin in reducing the ACTH response to hypoglycaemia suggested that it might prove useful in Nelson's syndrome. These results show that it is not indicated in these patients.

The effect of streptozotocin-induced diabetes on pituitary and hypothalamic endorphin equivalents.

This study examines the effect of experimentally induced diabetes mellitus in rats on tissue concentrations of opioid peptides in the neurointermediate lobe (NIL), anterior pituitary (AP) and hypothalamus. Diabetic animals were found to have a marked increase in endorphin equivalents, measured by opiate receptor binding assay, in the NIL whereas no change was observed in beta endorphin-like immunoreactivity (beta ELI) or ACTH measured by RIA. These results may indicate the presence of a feedback mechanism and suggest the possibility that opioid peptides may be physiologically important in the maintenance of glucose homeostasis.

Value and feasibility of screening women attending STD clinics for cervical chlamydial infections.

A chlamydial screening service was provided in Bristol over a three-month period for women attending the sexually transmitted disease (STD) clinic either for the first time or with a new complaint. Isolation of Chlamydia trachomatis was attempted in cytochalasin-treated McCoy cells. Of 919 specimens, valid results were obtained in 796. Chlamydial infections were identified and treated in 154 (19%) of these 796 women. Chlamydia were isolated from 52 (37%) of 152 female partners of men with nongonococcal urethritis (NGU); these patients already routinely receive treatment with tetracylcines in this clinic. The remaining 102 infections (34 (48%) of 71 women with gonorrhoea and 68 (12%) of the other 573 women) would have been unrecognised and usually untreated without chlamydial isolation studies. These figures confirm the need to provide chlamydial diagnostic services for selected STD clinic attenders.

Herpes genitalis and circumcision.

214 patients with genital herpes infection proven by culture and a control group of 410 other patients were included in a retrospective study devised to investigate the relationship of circumcision to genital HSV infection in the male. The percentage of patients circumicised in the control group was significantly larger than in the herpes group (P less than 0-01). The was not found to be the case for other sexually-transmitted diseases apart from monilial balanitis. There was also a significant difference in contraceptive methods in the two groups, barrier methods being used less ofter than other methods in the herpes group and the reverse in the control group. It is concluded that there is a positive relationship between absence of circumicision and genital HSV infection, but that a prospective study should be undertaken to confirm these results.