Lower motor neuron dysfunction associated with human immunodeficiency virus infection

OBJECTIVE

The association of human immunodeficiency virus with a clinical picture of motor neuron disease is uncommon, with three cases reported to date. This case represents an additional case of a human immunodeficiency virus-infected patient with apparent motor neuron disease.

DESIGN

Single patient case report.

SETTING

Large urban public hospital.

PATIENT

A 45-year-old human immunodeficiency virus-positive Hispanic man who presented with muscle wasting, fasciculations, areflexia, cranial nerve deficits, and weakness progressing to a complete quadriplegia.

RESULTS

Electrophysiologic data showed evidence of diffuse denervation with normal sensory and motor nerve conductions and no evidence of demyelination. Electromyography showed diffuse sharp waves and fibrillation.

CONCLUSIONS

This case demonstrates a progressive motor neuron dysfunction in a patient positive for the human immunodeficiency virus and provides additional evidence that infection with the human immunodeficiency virus should be considered in the differential diagnosis of apparent motor neuron disease.

Metastable CO binding sites in the photoproduct of a novel cooperative dimeric hemoglobin

The infrared absorption spectrum of the CO-photoproduct from Scapharca inaequivalvis hemoglobin (Hbl) at 10 K yields only a single line in the "B" state region at 2132 cm-1. This is the same frequency as the B1 line observed in photodissociated vertebrate HbCO and MbCO. No evidence was found for the B2 line detected in vertebrate hemoglobins and myoglobin in the 2118-2120 cm-1 region. These data demonstrate that the protein does not have the same conformationally accessible ligand-binding sites as do vertebrate hemoglobins and myoglobins. The absence of the B2 line indicates that only a single weak site is accessible to the photolyzed CO molecule. These results are in accord with geminate rebinding experiments and ligand escape pathway calculations which have shown that the distal properties of Hbl are distinct from those of tetrameric hemoglobins and vertebrate myoglobins.

Solvent oxygen is not incorporated into N10-formyltetrahydrofolate in the reaction catalyzed by N10-formyltetrahydrofolate synthetase

The mechanism of the reaction catalyzed by N10-formyltetrahydrofolate synthetase involves the formation of formyl phosphate as an intermediate which then formylates tetrahydrofolate at the N-10 position. Previous studies demonstrated that the non-enzymic formylation of tetrahydrofolate by formyl phosphate occurs exclusively at the more nucleophilic 5-nitrogen in the reduced pyrazine ring. The experiments described in this report were designed to determine whether N5-formyltetrahydrofolate might be the first product to be formed on the enzyme, followed by formyl transfer to the 10-nitrogen via the cyclic intermediate N5,10-methenyltetrahydrofolate. If this were the case, oxygen from solvent H2O would be incorporated into the formyl group of the N10-derivative. By conducting the reaction in a 1:1 mixture of [16O]H2O and [18O]H2O and using 13C NMR spectroscopy we show that no 18O is incorporated into the product and conclude that the reaction proceeds via a direct formylation of the N-10 position by formyl phosphate.

Protein-heme interactions in hemoglobin from the mollusc Scapharca inaequivalvis: evidence from resonance Raman scattering

Resonance Raman spectra of the Scapharca inaequivalvis homodimeric hemoglobin (HbI) have been measured for the ligand-bound and ligand-free ferrous forms of the protein. In the deoxy derivative, the iron-histidine (Fe-His) stretching mode, proposed as a marker of the oxygen affinity and a conduit linking the hemes to the subunit interface, gives rise to a Raman peak centered at 203 cm-1, an unusually low frequency compared to that reported for other hemoglobins and myoglobins. In the CO-bound derivative, three isotope-sensitive lines at 517, 583, and 1945 cm-1 have been assigned to the Fe-CO stretching, Fe-C-O bending, and C-O stretching modes, respectively. From the frequencies of these modes and from their relative intensities, the Fe-C-O geometry appears to be tilted from axial coordination and shows a bending angle which has been estimated to be about 171 +/- 5 degrees. For the oxygen derivative, only one isotope-sensitive peak has been detected at 570 cm-1, in line with the values found for myoglobin and other hemoglobins. Resonance Raman spectra of HbI modified with p-(chloromercuri)benzoate (PMB) at Cys92 have been measured in parallel with those of the native protein. Despite the large increase in oxygen affinity produced by the PMB modification, the frequency of the Fe-His stretching mode is unshifted in the deoxy derivative.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of different doses of norethisterone on ovarian function, serum sex hormone binding globulin and high density lipoprotein-cholesterol

The ovarian effects of different doses of norethisterone (NET) were compared in 45 normally menstruating women in order to find the lowest effective dose of the Chinese NET "visiting pill". Subjects were randomly divided into 3 groups. Each subject in each group was taking 0.5, 1.5 or 3.0 mg per day from days 5 to day 18 of the cycle. Blood samples were taken on days 5, 8, 11, 14, 17, 20, 23, 26 and 29 of the cycle. Serum oestradiol (E2), progesterone (P), sex hormone binding globulin (SHBG), high density-lipoprotein cholesterol (HDL-C), and NET concentrations were measured. Ovulation, delayed ovulation, ovulation inhibition and follicular activity were classified by the analysis of the peripheral serum levels of sex hormones. Ovulation occurred in 7 women in the 0.5 mg group, in 2 women in the 1.5 mg group and in none of the 3.0 mg group. Mean serum SHBG levels were reduced progressively by 6.6% (Group 0.5), 15.5% (Group 1.5) and 23.4% (Group 3.0). There were no significant changes in HDL-C levels in any group. There was a significant correlation of mean serum NET concentrations with dose. The lack of complete inhibition of ovulation in most women in the 1.5 mg and 0.5 mg groups might suggest that the dose of NET required when used as a visiting pill could not be reduced below 3.0 mg.

Heme-heme interactions in a homodimeric cooperative hemoglobin. Evidence from transient Raman scattering

The comparison of the resonance Raman spectrum of the deoxy dimeric hemoglobin (HbI) from the Arcid clam, Scapharca inaequivalvis, to its CO photoproduct at 10 ns reveals several significant differences in the low frequency vibrational modes including those involving motions of the peripheral substituents on the heme such as the propionates. This finding reflects the involvement of the propionates in a hydrogen bonding network which connects the two heme groups across the subunit interface and is sensitive to ligand binding. A frequency difference in the iron-histidine stretching mode of 6 cm-1 in this invertebrate hemoglobin is substantially smaller than that detected in tetrameric vertebrate hemoglobins under similar conditions. Time evolution studies of the vibrational modes from the photoproduct demonstrate that the transient form relaxes to the deoxy structure concertedly with a half-life of 1 microseconds, the time scale in which tertiary relaxations of tetrameric hemoglobins occur. These data establish that the tertiary and quaternary structural changes take place on the same time scale and confirm a mechanism of cooperativity involving direct interaction between the two heme groups through the peripheral substituents. This direct structural communication provides a very tight linkage between the heme groups prohibiting modulation of the oxygen affinity by factors in the physiological milieu.

Theoretical framework for the design of purely real synthetic-discriminant-function-type correlation filters

A general algorithm for synthesizing purely real correlation filters in the frequency domain is developed by using the method of Lagrange multipliers. This method can be applied to filters that are derived by using linearly constrained quadratic minimization. The synthesis of purely real versions of minimum average correlation energy filters, minimum-variance synthetic discriminant functions, and other synthetic-discriminant-function-type filters is discussed to illustrate this approach. Their performance is found to be somewhat less than that of the original complex filters but still adequate for practical applications. The main advantage of this approach is that optimum purely real filters can be generated that are easy to implement in spatial light modulators without holograms and that yield the correlation output on the zero-order beam.

Isolation of a Drosophila gene encoding glutathione S-transferase

We have isolated a Drosophila gene, DmGST-2, that encodes glutathione S-transferase, a homo- or heterodimeric enzyme thought to be involved in detoxification of xenobiotics, including known carcinogens. The encoded protein has a primary sequence that is more similar to mammalian placental and nematode GSTs than that of a previously described Drosophila GST gene, herein referred to as DmGST-1. We provide a physical map of the gene and show that it specifies at least two mRNAs, measuring 1.9 and 1.6 kb, which differ only in the lengths of their 3' untranslated regions. Both of the mRNAs are present during all developmental stages. In situ hybridization of the DmGST-2 gene to larval polytene chromosomes places it within the 53F subdivision of chromosome 2, and Southern blotting to chromosomal DNA indicates that the gene has no close relatives within the Drosophila genome. Our results make possible molecular genetic approaches for further elaborating the function of glutathione S-transferases in insect development and physiology, in the metabolism of plant toxins, and in conferring insecticide resistance.

A cross-over study of three oral contraceptives containing ethinyloestradiol and either desogestrel or levonorgestrel

A randomised cross-over trial was performed to compare the pharmacodynamic actions of three low-dose oral contraceptives (OCs): Marvelon (150 micrograms desogestrel (DSG)+ 30 micrograms ethinyloestradiol (EE)), Mercilon (150 micrograms DSG + 20 micrograms EE) and Microgynon (150 micrograms levonorgestrel (LNG) + 30 micrograms EE). None of the OCs produced any significant changes in serum cholesterol, LDL-C and apoprotein B. Triglycerides were increased by the desogestrel OCs but not by Microgynon. The latter however increased the glucose and insulin responses to a glucose tolerance test whereas Marvelon and Mercilon had no effect. HDL-C increased with Marvelon, was unchanged with Mercilon and was decreased with Microgynon. Apoprotein AII was increased by all three OCs but only the DSG OCs increased apoprotein AI. All OCs produced similar increases in caeruloplasmin but the increase in SHBG was much greater with Marvelon and Mercilon than with Microgynon. Testosterone was reduced more with Microgynon than with the DSG OCs. Many of the changes reflect the strong anti-oestrogenic action of LNG on metabolic parameters compared to DSG. Except for the effect on HDL-C, there was little difference between Marvelon and Mercilon on metabolic parameters and this complements the findings from large-scale clinical trials of the two OCs. Mercilon, therefore provides a very satisfactory alternative to Marvelon.

Clinical Experience with an Activity Sensing DDDR Pacemaker Using an Accelerometer Sensor

The rate adaptive characteristics and pacemaker mediated tachycardia protection algorithm of an accelerometer based DDDR pacemaker were evaluated in 11 patients with bradycardia (seven atrioventricular block, four sick sinus syndrome). Rate adaptive programming was effected by collecting the acceleration level during a 3-minute moderate exercise ("tailoring" of sensor). In comparison with an externally attached piezoelectric sensor, the accelerometer sensor showed lower rate changes during external tapping of the pacemaker (16 +/- 3 vs 29 +/- 4 ppm, P less than 0.02) and applied direct pressure (1 +/- 1 vs 40 +/- 3 beats/min, P less than 0.001) on the pacemaker. At nominal setting, the accelerometer sensor showed improved rate stability and higher rate response to jogging and standing, although responses to other daily activities and treadmill exercise were similar. Apart from changing the rate responsive slope, rate response could be improved by repeat "tailoring" of the sensor at a lower exercise level, resulting in better overall rate response characteristics. The ability of the rate monitoring software to collect acceleration levels for an activity and profile the projected rate response at different rate responsive settings allowed programming to be effected with the minimum amount of exercise testing. The pacemaker also discriminated atrial tachyarrhythmias from normal sinus response using the sensor to judge the appropriateness of the atrial rate, which correctly identified and prevented rapid ventricular tracking in two patients during atrial flutter/fibrillation.

The Use of Implantable Sensors for the Control of Pacemaker Mediated Tachycardias: A Comparative Evaluation Between Minute Ventilation Sensing and Acceleration Sensing Dual Chamber Rate Adaptive Pacemakers

The role of implantable sensors to control pacemaker mediated tachycardias was investigated in 16 patients with two different dual chamber rate adaptive (DDDR) pacemakers, which sensed eiter minute ventilation (DDDR-Meta, nine patients) or body acceleration (Relay, seven patients). Successive atrial sensed events beyond a programmable rate occurring in the absence of detection of exercise by the sensors were considered to represent retrograde conduction or atrial arrhythmias, and the pacemakers responded by either a mode shift from DDDR to ventricular rate adaptive (VVIR) pacing (DDDR-Meta) or by tracking at an interim rate, the so-called conditional ventricular tracking limit (CVTL, Relay). In the unipolar atrial sensing mode, myopotential sensing (MPI) and external chest wall stimulations (CWS) at 250 beats/min were induced to be preferentially sensed by the atrial channel to simulate the conditions of atrial arrhythmias. In the DDD mode, these maneuvers resulted in ventricular responses of 88 +/- 3 beats/min and 110 +/- 3 beats/min for MPI and CWS, respectively. The pacing rate was significantly reduced in the DDDR mode with the sensors correctly detecting and responding to the sensed abnormal atrial signals (68 +/- 5 beats/min during MPI and 71 +/- 5 beats/min during CWS, P less than 0.005 compared with the corresponding DDD rate). One patient with a Relay pacemaker developed spontaneous atrial flutter and the ventricular tracking responses were 140 and 85 beats/min in the DDD and DDDR pacing modes, respectively. Thus MPI and CWS are useful bedside testing methods to assess pacemaker response during atrial arrhythmias. The use of implantable sensors to judge the appropriateness of atrial rate is a new approach to the management of pacemaker mediated tachycardias.

21-aminosteroids interact with the dopamine transporter to protect against 1-methyl-4-phenylpyridinium-induced neurotoxicity

U-78518F, a 21-aminosteroid from the novel family of lipid peroxidation inhibitors (lazaroids), increased survival of dopamine (DA) neurons in mesencephalic cell cultures incubated with the neurotoxin 1-methyl-4-phenylpyridinium (MPP+). Protection against DA neuron death occurred with increasing concentrations of U-78518F up to 30 microM. Non-specific toxicity produced with higher concentrations of MPP+ was not affected by the lazaroid. U-78518F inhibited cellular uptake of [3H]MPP+ and [3H]DA, but not that of gamma-[3H]aminobutyric acid. In human striatal membrane preparations, U-78518F competed with [3H]mazindol for binding to the DA transporter, with a calculated Ki value of 10 microM. Two of four lazaroids tested inhibited [3H]DA uptake in the cell culture system. The protective effects of 21-aminosteroids in MPP(+)-induced neurotoxicity are, in part, a function of the interaction of these agents with the DA transporter.

[Cerebral germinoma]

16 cases of cerebral germinoma are reported. This tumor is comparatively rare. Since it is usually located in pineal and easily be confused with pineloma or ectopic pinealoma, its terminology, source of the tumor tissue, histopathological characteristics, diagnosis and differential diagnosis are discussed by the authors. According to the high mortality of the operative treatment, the radiotherapy is suggested.

A pharmacodynamic and pharmacokinetic study of the Chinese No. 1 pill

A pharmacodynamic and pharmacokinetic study of the Chinese No. 1 pill, a combined oral contraceptive containing 35 micrograms ethynyloestradiol (EE) and 600 micrograms norethisterone (NET), was performed in 29 women over a period of six months. Blood samples for analysis were taken during a pretreatment cycle, the first and 6th treatment cycles and post-treatment. Minor changes in carbohydrate metabolism occurred and these were particularly noticeable when the incremental areas under the serum concentration-time curves for both glucose and insulin in response to a glucose tolerance test were calculated. No changes occurred in the serum glycosylated haemoglobin levels. The serum concentrations of all the lipids measured (total cholesterol, triglycerides, LDL-C, HDL-C and apolipoproteins AI, AII and B) were significantly increased on treatment as were levels of Factor X, SHBG and caeruloplasmin whereas antithrombin III decreased. In 38 of the 40 treatment cycles, ovulation was suppressed. In one cycle serum oestradiol and progesterone levels showed a typical ovulatory pattern and in another there was evidence of follicular activity without ovulation. Serum EE concentrations showed a similar pattern in both treatment cycles showing that co-administration of NET did not affect EE metabolism. Serum NET levels were higher in the 6th than in the first treatment cycles. On comparing pharmacodynamic and pharmacokinetic parameters, the only statistically significant correlations were between the percentage change in triglycerides and SHBG and serum NET, but not EE concentrations, and between apolipoproteins AI and serum EE.

Cat-P300 present after association cortex ablation

The cat-P300 is a positive endogenous potential, larger to a stimulus when rare than when frequent, with a latency of 200-500 msec. The role of polysensory association cortex, postulated to be important in human P300 generation, was assessed in the cat. EEG was recorded in 13 awake cats from a skull screw at the vertex. Stimuli included frequent (P = 0.80) 1 kHz and rare (P = 0.10) 2 kHz tone pulses with probabilities counterbalanced across 260-trial blocks. After 12 preoperative sessions, bilateral ablations were made of pericruciate cortex (4 cats), anterior lateral and medial suprasylvian gyri (4 cats) and all 3 areas (5 cats). Postoperatively, all 13 cats showed a P300 across 12 recording sessions. Thus polysensory association cortex is not essential for generation of the cat-P300.

Retinoic acid regulation of the expression of retinoic acid receptors in wild-type and mutant embryonal carcinoma cells

The embryonal carcinoma cell line P19 undergoes terminal differentiation upon induction by retinoic acid (RA). The effects of RA on the retinoic acid receptor (RAR) mRNA level were investigated in P19 cells and an RA non-responsive mutant RAC65. RA induced a rapid accumulation of RAR alpha within 2 h and this was followed by an increase in the RAR beta mRNA. RAC65 cells differed from P19 cells in that the accumulation of RAR alpha mRNA was delayed and that an aberrant pattern of RAR alpha transcript was observed.

Determination of the complete nucleotide sequence of HBV adr NC-1 DNA

On the basis of sequencing the large DNA-fragments which have been inserted into M13mp8, we design a simple strategy to determine the complete nucleotide sequence of HBV adr NC-1 DNA with chain termination method. The whole genome is 3195 nucleotides long. Five reading frames are observed. The gene location and organization are shown.

Molecular cloning and expression of salmon pituitary hormones

A cDNA library was prepared from chinook salmon pituitaries. Growth hormone (GH), prolactin (PRL) and the β subunit of gonadotropin (GTH) genes were screened using synthetic oligonucleotides as probes. Full size cDNA clones coding for these polypeptide hormones were isolated and characterized. The cDNA sequences for PRL and βGTH have been reported earlier from our laboratories. The cDNA clone for GH contains 1148 bp and codes for a preGH of 210 amino acids. The chinook salmon GH, reported in the present investigation, differs from chum salmon GH in only 1 amino acid, and from coho salmon GH in 5 amino acids. Plasmids containing modified nucleotide sequences coding for GH, PRL and βGTH were constructed individually into an expression vector using the heat-inducible λ pL promotor. Mature PRL, GH and unglycosylated βGTH were expressed in the bacteria at elevated temperature.

Effect of some oral contraceptives on serum concentrations of sex hormone binding globulin and ceruloplasmin

Serum SHBG and ceruloplasmin (CP) concentrations were measured in women throughout a cycle of treatment with four oral contraceptives. In women receiving 150 micrograms levonorgestrel (LNG) daily both SHBG and CP decreased. SHBG also decreased, but CP increased, in women receiving ethynyloestradiol (EE) 30 micrograms with LNG 150 micrograms. In women taking 35 micrograms EE with either 600 micrograms or 1000 micrograms norethisterone, increases in CP were similar but SHBG increased more with the lower dose. Serum concentrations had not returned to pretreatment levels by eight days after cessation of dosing. The findings are compared with similar results for women taking 30 micrograms or 50 micrograms EE or an EE,LNG triphasic formulation. Serum concentrations of the gestagens were also measured. Increases in these concentrations when the gestagen was administered with EE to levels higher than expected from administration of the gestagen alone cannot be explained by increased binding to SHBG but are more likely to be due to changes in their metabolism. Differences in the responses of ostensibly closely related proteins of hepatic origin such as SHBG and CP to the oral contraceptives demonstrate that neither can be extrapolated to other pharmacodynamic responses.