The level of the serum opsonin, mannan-binding protein in HIV-1 antibody-positive patients.

The concentrations of mannan-binding protein (MBP) in consecutive samples from 10 HIV+ persons were estimated using an ELISA based on polyclonal rabbit anti-MBP. The changes in MBP with time were similar in HIV+ and HIV- persons, and did not appear to be of clinical significance. MBP was determined in a further 70 persons found HIV-1+ during a period of 2.5 years (1984-1986). Out of the total of 80 patients, 32 have by now died from AIDS. According to the serum level of MBP the HIV-infected persons were grouped into high (> 650 ng MBP/ml), intermediate (101-650 ng/ml), and low MBP (< 101 ng/ml). At the termination of the study the frequency of deaths/total in each of the groups were: high MBP, 14/39 (36%); intermediate MBP, 12/26 (46%); and low MBP, 6/14 (43%). There was no association between the MBP level of the individual and the progressive loss of CD4+ T cells, and the level of MBP was not predictive for the length of time between the detection of HIV antibodies and development of AIDS, nor for the duration of AIDS before death occurred. The number of HIV+ persons without detectable MBP (10%) was significantly higher than previously reported for healthy persons (2.4%, P = 0.027). The course of HIV infection does not seem to be influenced by the level of MBP, nor does the antimicrobial activity of MBP appear to affect the progression of AIDS. Further studies are required to substantiate the significance of absence of MBP in the susceptibility to HIV.     

Effect of sodium ions on penicillin-induced epileptiform activity in vitro

Summary Intra- and extracellular recordings were obtained from the CA1 region of guinea pig hippocampal slices maintained in vitro. We studied the effect of reducing the extracellular sodium concentration on penicillin-induced epileptiform responses.In control experiments, Tris and choline were assayed as sodium substitutes. Choline was found unsuitable, since it induced repetitive firing in the absence of any convulsant agent. Replacement of 50% of the extracellular sodium ([Na⁺]_o) with Tris reduced the amplitude of the presynaptic fiber volley, the field EPSP, and the population spike. Intracellular studies showed that when [Na⁺]_o was lowered, action-potential amplitudes were reversibly depressed by an amount close to that predicted by the Nernst relation.Orthodromically elicited epileptiform discharges, induced by penicillin, were reduced in a low-sodium medium when constant stimulus currents were employed. If orthodromic stimulus strengths in normal and low-sodium states were equated on the basis of the field-EPSP amplitude, no significant diminution of the depolarizing-wave component of the epileptiform response was observed. These results suggest that a synaptic component underlies penicillin-induced epileptiform discharges.Supported by grants from the Norwegian Research Council for Science and the Humanities and by NIH grants NS 11535 and NS 15772     

IgG antibodies to purified Aspergillus fumigatus antigens determined by enzyme-linked immunosorbent assay

IgG antibodies to three purified Aspergillus fumigatus antigens were determined by enzyme-linked immunosorbent assay (ELISA) in sera from 26 patients with definite pulmonary aspergillosis (group 1), 23 patients with suspected pulmonary aspergillosis (group 2), 8 patients with precipitating antibodies to A. fumigatus of undetermined clinical significance (group 3), and 113 healthy blood donors (group 4). With a 470,000-dalton antigen fraction ELISA values exceeded the upper range of group 4 (0.72) in 92, 91 and 13% of cases in groups 1, 2 and 3, respectively. With a 250,000-dalton antigen fraction the figures were 96, 78 and 13%, respectively (upper range of group 4 = 0.25). With an antigen fraction of 25,000-50,000 daltons the figures were 96, 65 and 13%, respectively (upper range of group 4 = 0.18). In 48 of 49 cases of definite or suspected aspergillosis (groups 1 + 2) ELISA values with at least one antigen exceeded the upper range of controls (group 4). It appears that antibody determination with these three antigen fractions may have a high diagnostic sensitivity.     

Distribution of whaleworm (Anisakis simplex,Nematoda, Ascaridoidea) L3 larvae in three species of marine fish; saithe (Pollachius virens (L.)), cod (Gadus morhua L.) and redfish (Sebastes marinus (L.)) from Norwegian waters

The frequency distribution of Anisakis simplex L3 larvae between host tissues was investigated in three host species: saithe, cod and redfish. Fish were sampled from Norwegian coastal waters and examined for the presence of A. simplex in muscle and viscera. In all three of the host species, A. simplex larvae were most frequently detected in the viscera; the percentages of total infection for saithe, cod and redfish were 99.6%, 97.8% and 88.0%, respectively. In general, the distribution patterns of A. simplex L3 between muscle and viscera were not significantly affected by host size. The observations that distributions vary between species and are not affected by host size do not support an earlier hypothesis which states that A. simplex L3 distributions are determined by an optimal pre-encapsulation migratory distance within host tissues. In contrast, it is suggested that A. simplex L3 distributions are governed by the conditions encountered within host tissues, and are possibly related to the availability of nutrients. Received: 9 July 1997 / Accepted: 15 September 1997     

Muscle fibre type,efficiency, and mechanical optima affect freely chosen pedal rate during cycling

This study investigated the variation in freely chosen pedal rate between subjects and its possible dependence on percentage myosin heavy chain I (%MHC I) in m. vastus lateralis, maximum leg strength and power, as well as efficiency. Additionally, the hypothesis was tested that a positive correlation exists between percentage MHC I and efficiency at pre-set pedal rates but not at freely chosen pedal rate. Twenty males performed cycling at low and high submaximal power output ( approximately 40 and 70% of the power output at which maximum oxygen uptake (VO(2max)) was attained at 80 r.p.m.) with freely chosen and pre-set pedal rates (61, 88, and 115 r.p.m.). Percentage MHC I as well as leg strength and power were determined. Freely chosen pedal rate varied considerably between subjects: 56-88 r.p.m. at low and 61-102 r.p.m. at high submaximal power output. This variation was only partly explained by percentage MHC I (21-97%) as well as by leg strength and power. Interestingly, %MHC I correlated significantly with the pedal rate at which maximum peak crank power occurred (r = -0.81). As hypothesized, %MHC I and efficiency were unrelated at freely chosen pedal rate, which was in contrast to a significant correlation found at pre-set pedal rates (r = 0.61 and r = 0.57 at low and high power output, respectively). Conclusions: Subjects with high percentage MHC I chose high pedal rates close to the pedal rates at which maximum peak crank power occurred, while subjects with low percentage MHC I tended to choose lower pedal rates, favouring high efficiency. Nevertheless, the considerable variation in freely chosen pedal rate between subjects was neither fully accounted for by percentage MHC I nor by leg strength and power. Previously recognized relationships between percentage Type I ( approximately %MHC I) and efficiency as well as between pedal rate and efficiency were confirmed for pre-set pedal rates, but for freely chosen pedal rate, these variables were unrelated.     

Long QT syndrome with a high mortality rate caused by a novel G572R missense mutation in KCNH2

In a four-generation family with long QT syndrome, syncopes and torsades de pointes ventricular tachycardia (TdP) were elicited by abrupt awakening in the early morning hours. The syndrome was associated with a novel KCNH2 missense mutation, G572R, causing the substitution of a glycine residue at position 572, at the end of the S5 transmembrane segment of the HERG K(+)-channel, with an arginine residue. This segment is involved in the channel pore and the mutation may cause a reduction in the rapidly activating delayed rectifier K+ current (Ikr), or changed gating properties of the ion channel, leading to prolonged cardiac repolarization. The electrocardiograms of affected persons showed prolonged QT interval and notched T waves. Despite treatment with atenolol, 200 mg twice daily, the proband still experienced TdP episodes. Three untreated relatives of the proband died suddenly, and unexpectedly, at 18, 32, and 57 years of age. The G572R mutation is thus associated with a high mortality rate, and the clinical presentation illustrates that some mutations may not be controllable by just beta-blockade.     

Screening for cervical cancer in HIV-infected women receiving care in the United States

OBJECTIVE: We examined the sociodemographic, clinical and provider factors associated with screening for cervical cancer among HIV-infected women. METHODS: We studied a national sample representing 43,490 women receiving treatment of HIV infection who completed first follow-up surveys of the HIV Cost and Service Utilization Study (HCSUS). All women were asked, "In the past 12 months, have you had a Pap test?" Women reporting an abnormal Pap test result were asked whether they had been told antibiotics could cure abnormal cells, and whether they were scheduled for another Pap test or for a colposcopy within 3 months. RESULTS: Of the population represented, 81% had had a Pap test in the past 12 months. Women who reported having a gynecologist and primary care physician at the same clinical site were almost twice as likely (odds ratio, 1.9; 95% confidence interval, 1.3-3.0) as other women to report Pap testing. Among women who reported abnormal Pap test results and were not told antibiotics could cure abnormal cells, 95% were scheduled for a repeat Pap test or colposcopy, but 15% of the women had not received their repeat Pap test or colposcopy. CONCLUSION: Although Pap test rates and appropriate referral for abnormal findings were high among HIV-tested women, many women with initially abnormal Pap test results did not actually receive follow-up Pap testing or colposcopy. Providing gynecologic care at the same site as primary HIV care would likely improve delivery of needed gynecologic care for women.     

Cloning and sequence analysis of the major outer membrane protein gene of Chlamydia psittaci 6BC.

The gene encoding the major outer membrane protein (MOMP) of the psittacine Chlamydia psittaci strain 6BC was cloned and sequenced. N-terminal protein sequencing of the mature MOMP indicated that it is posttranslationally processed at a site identical to the site previously identified in the MOMP of Chlamydia trachomatis L2. The nucleotide sequence of the C. psittaci 6BC MOMP gene was found to be 67 to 68% identical to those of human C. trachomatis strains, 73% identical to that of Chlamydia pneumoniae IOL-207, 79% identical to that of the C. psittaci guinea pig inclusion conjunctivitis strain, GPIC, and 83% identical to that of the C. psittaci ovine abortion strain S26/3. In contrast, the 6BC sequence was found to be greater than 99% identical to the sequences reported for two strains of C. psittaci, A22/M and Cal-10 meningopneumonitis, believed to be of nonpsittacine avian origin. Monoclonal antibody analysis confirmed the nonpsittacine avian origin of A22/M but identified the Cal-10 strain from which the MOMP gene was previously sequenced as a psittacine strain. These results confirm that psittacine and nonpsittacine avian strains of C. psittaci are closely related and distinct from the mammalian guinea pig inclusion conjunctivitis and ovine abortion strains of C. psittaci.     

Voltage-gated ion channels in nociceptors: modulation by cGMP

In tissue or nerve injury, proinflammatory mediators are released that can modulate a variety of ion channels found in nociceptors. The changes in channel activity, which primarily occurs through changes in intracellular pathways, may lead to the pathological states of hyperalgesia and allodynia. To understand further the regulatory mechanisms underlying the changes in channel activity, we used whole cell patch-clamp recordings from capsaicin-sensitive nociceptive neurons in rat trigeminal ganglion neurons to examine how the cGMP-dependent pathways may regulate ion channel function. Addition of the 8-(4-chlorophenylthio)-3',5' (CPT)-cGMP, a membrane permeant modulator of ion channels, decreased the number of evoked action potentials by 36% and inhibited the tetrodotoxin-resistant (TTX-R) sodium currents and IA potassium currents by 37 and 32%, respectively. Delayed rectifier potassium (IK) currents were unaffected, suggesting that the effects of CPT-cGMP are unlikely to arise from a nonspecific effect on channel activity as a consequence of the adsorption of amphipathic CPT-cGMP molecules to the membrane's bilayer component. This conclusion was reinforced by the lack of changes in gramicidin A channel function in the presence of CTP-cGMP. In summary, the activation of the cGMP-dependent pathways reduces nociceptor excitability, in part, by decreasing the activity of voltage-gated TTX-R sodium channels. This pathway may be a target for efforts to produce selective analgesics.