Potent antiretroviral therapy of primary human immunodeficiency virus type 1 (HIV-1) infection: partial normalization of T lymphocyte subsets and limited reduction of HIV-1 DNA despite clearance of plasma viremia

Antiretroviral therapy commenced during primary human immunodeficiency virus type 1 (HIV-1) infection (PHI) may limit the extent of viral replication and prevent early loss of HIV-specific CD4 lymphocyte function. We studied the effect of current standard therapy (2 nucleoside analogues and a protease inhibitor) in 16 patients with symptomatic PHI. In the 13 patients who completed 1 year of treatment, plasma HIV RNA was <50 copies/mL and median CD4 cell counts were comparable to HIV-uninfected controls, with naive (CD45RA+CD62L+), primed (CD45RO+), and T cell receptor Vbeta subsets all within normal ranges. However, HIV-1 DNA levels in treated and untreated PHI patients were similar. Furthermore, CD8 cell counts remained elevated, including activated (CD38+HLA-DR+), replicating (Ki-67+), and cytotoxic (perforin+CD28-) lymphocytes. In conclusion, early antiretroviral therapy resulted in clearance of viremia and prevented loss of crucial CD4 subsets. The persistence of HIV-1 DNA together with increased CD8 T lymphocyte turnover and activation indicate continued expression of viral antigens.

Glutamate and antimitotic agents induce differentiation, p53 activation, and apoptosis in rodent neostriatal cell lines immortalized with the tsA58 allele of SV40 large T antigen

The tsA58 allele of SV40 large T antigen has the ability to immortalize cells, which is thought to be due, in part, to binding of p53 protein by T antigen at 33 degrees C. At the nonpermissive temperature (39.5 degrees C), it is thought that p53 is released, inducing growth arrest, vulnerability to apoptosis, and loss of the immortal phenotype. In cell lines derived from the rat neostriatum immortalized with tsA58, the toxic agents Adriamycin, cytosine arabinoside, and glutamate induced apoptosis and increased p53 activity and differentiation. The apoptosis and p53-inducing effects of the drugs were not greater at 39.5 degrees C compared to 33 degrees C, suggesting that p53 is not effectively blocked even at 33 degrees C. Growth arrest was not induced under most treatment conditions despite p53 induction. On the other hand, process extension was enhanced at 39.5 degrees C compared to 33 degrees C. Therefore, these cell lines are temperature sensitive with respect to differentiation, but not growth regulation or apoptosis.

Auricular rehabilitation with bone-anchored titanium implants

OBJECTIVE

To evaluate the effectiveness of the bone-anchored titanium implants in auricular reconstructions.

STUDY DESIGN

Six patients who received implants for an auricular reconstruction were followed prospectively. Four patients had lost their ears to cancer, and the other two had congenital aural atresia.

METHODS

All patients were thoroughly evaluated by the reconstruction team, which included a surgeon, a prosthodontist, and a facial prosthetist. Three patients were evaluated audiologically for a bone-anchored hearing aid. Four patients received implants in a single-stage procedure, and two underwent a two-stage procedure. A gold bar with retaining clips was used to anchor the prosthetic ear in four patients, and magnets were used in the remaining two.

RESULTS

All six patients are completely satisfied with their reconstructions. No failures, extrusions, or bony complications were encountered. One patient had recurrent dermatitis, which subsided when his gold bar was replaced with magnets.

CONCLUSION

Implanted under the guidance of an appropriate prosthetic team, bone-anchored titanium implants provide patients with a safe, reliable, adhesive-free method to anchor auricular prostheses with recovery of their normal appearance.

Junction road accidents during cross-flow turns: a sequence analysis of police case files

In-depth studies of behavioural factors in road accidents using conventional methods are often inconclusive and costly. In a series of studies exploring alternative approaches, 200 cross-flow junction road accidents were sampled from the files of Nottinghamshire Constabulary, UK, coded for computer analysis using a specially devised Traffic Related Action Analysis Language, and then examined using different computational and statistical techniques. For comparison, the same analyses were carried out on 100 descriptions of safe turns, and 100 descriptions of hypothetical accidents provided by experienced drivers. The present study employed a range of sequence analysis techniques to examine the patterns of events preceding accidents of different types. Differences were found between real accidents, hypothetical ones and safe turns; between accidents turning onto and off a road with the right of way; between the accidents of younger and older drivers; between accidents on minor roads and major roads; and between the accident expectations (but not the real accidents) of male and female drivers. Pairs of successive events often provided particularly good cues for discriminating accident types.

Quantification of the enhanced backscatter phenomenon from an intravenous and an intra-arterial contrast agent

The phenomenon of enhanced backscatter from myocardial contrast agents was studied using two examples, a robust thicker-walled, intra-arterial agent (AIP 201) and a smaller thinner-walled, intravenous agent (Quantison). Both agents are composed of albumin-encapsulated microbubbles. Samples of the agents were inserted into an in vitro phantom and insonated under different scanning regimes. Upon insonation, Quantison exhibited a pronounced increase in mean backscatter at medium and low concentrations, which decreased dramatically with increasing number of frames of insonation. At high concentrations, no dramatic decrease or increase in mean backscatter was observed over the period of the experiment. AIP 201 exhibited an overall decrease in mean backscatter with increasing number of frames of insonation. These results suggest that the difference in size and wall thickness of the contrast microcapsules can significantly affect the behaviour of the contrast agents in an ultrasound field.

Pregnancy complicated by autoimmune polyglandular syndrome type II: a case report

Autoimmune polyglandular syndrome may complicate pregnancy and be confused with hyperemesis gravidarum as a cause of hypoglycemia and electrolyte imbalance in the first trimester of pregnancy. Autoimmune polyglandular syndromes are uncommon disorders characterized by the development and presentation of multiple endocrine and organ dysfunction. To our knowledge, we present the first case of an autoimmune polyglandular syndrome complicating pregnancy. A 26-year-old woman, gravida 5 para 3 at 12 weeks gestation, presented with hyperemesis and signs and symptoms consistent with adrenal insufficiency and hypothyroidism. Evaluation revealed autoimmune polyglandular syndrome type II. Autoimmune polyglandular syndromes are a myriad group of diseases characterized by polyglandular dysfunction. These syndromes should be kept in mind when dealing with pregnant patients presenting with hyperemesis and an electrolyte imbalance who do not improve with the usual treatment for hyperemesis. An endocrine dysfunction such as polyglandular syndrome may exist.

A cell cycle-regulated adenine DNA methyltransferase from Caulobacter crescentus processively methylates GANTC sites on hemimethylated DNA

The kinetic properties of an adenine DNA methyltransferase involved in cell cycle regulation of Caulobacter crescentus have been elucidated by using defined unmethylated or hemimethylated DNA (DNAHM) substrates. Catalytic efficiency is significantly enhanced with a DNAHM substrate. Biphasic kinetic behavior during methyl incorporation is observed when unmethylated or DNAHM substrates are used, indicating that a step after chemistry limits enzyme turnover and is most likely the release of enzyme from methylated DNA product. The enzyme is thermally inactivated at 30 degrees C within 20 min; this process is substantially decreased in the presence of saturating concentrations of DNAHM, suggesting that the enzyme preferentially binds DNA before S-adenosylmethionine. The activity of the enzyme shows an unusual sensitivity to salt levels, apparently dissociating more rapidly from methylated DNA product as the salt level is decreased. The enzyme acts processively during methylation of specific DNA sequences, indicating a preferred order of product release in which S-adenosylhomocysteine is released from enzyme before fully methylated DNA. The kinetic behavior and activity of the enzyme are consistent with the temporal constraints during the cell cycle-regulated methylation of newly replicated chromosomal DNA.

Behavioural factors in accidents at road junctions: the use of a genetic algorithm to extract descriptive rules from police case files

In-depth studies of behavioural factors in road accidents using conventional methods are often inconclusive and costly. To explore an alternative approach, 200 cross-flow junction road accidents were sampled from the files of Nottinghamshire Constabulary, England, coded for computer analysis using a specially devised 'Traffic Related Action Analysis Language', and then examined using a genetic algorithm (or 'rule-finder' program). For comparison, the same analyses were carried out on 100 descriptions of safe turns, and 100 of hypothetical accident descriptions provided by experienced drivers. A number of findings emerged, distinguishing between accidents turning onto and off major roads; those of younger and older drivers; those that resulted in injury or in damage only; and so on. The study suggests that multiple case-studies based on police case files could be very promising, provided homogeneous samples of accidents are used. Genetic algorithms could play a useful role in preliminary assessment, but an 'information bottleneck' remains to be overcome in capturing enough detail from each case for analysis.

How Zantac became the best-selling drug in history

Glaxo's Zantac began its dominance of the acid/peptic marketplace with a launch strategy, taking advantage of the established Roche sales force to rapidly promote the product. Educational symposia for physicians were instrumental in disseminating both disease and product information to primary care physicians and specialists. This technique not only pleased physicians (more referrals), but also increased public awareness of gastrointestinal disease, further expanding the patient market. Several novel marketing strategies contributed to Zantac's success, including the public-service announcements, celebrity media tours, and consumer-awareness bulletins, which brought the drug to the lay public and encouraged individuals to seek advice from their physicians.

Diagnostic strategies for pulmonary arteriovenous fistula in pregnancy

Pulmonary arteriovenous malformations (PAVMs) are a documented cause of hemoptysis, and usually necessitate pulmonary angiography for a definitive diagnosis. However, the diagnosis can become more problematic in pregnancy. We recently saw a young woman in her fifth month of pregnancy with hemoptysis, who was found to have multiple PAVMs. We report this case to highlight the various non-invasive methods of making this diagnosis.

The CcrM DNA methyltransferase is widespread in the alpha subdivision of proteobacteria, and its essential functions are conserved in Rhizobium meliloti and Caulobacter crescentus

The Caulobacter crescentus DNA methyltransferase CcrM (M.CcrMI) methylates the adenine residue in the sequence GANTC. The CcrM DNA methyltransferase is essential for viability, but it does not appear to be part of a DNA restriction-modification system. CcrM homologs are widespread in the alpha subdivision of gram-negative bacteria. We have amplified and sequenced a 258-bp region of the cerM gene from several of these bacteria, including Rhizobium meliloti, Brucella abortus, Agrobacterium tumefaciens, and Rhodobacter capsulatus. Alignment of the deduced amino acid sequences revealed that these proteins constitute a highly conserved DNA methyltransferase family. Isolation of the full-length ccrM genes from the aquatic bacterium C. crescentus, the soil bacterium R. meliloti, and the intracellular pathogen B. abortus showed that this sequence conservation extends over the entire protein. In at least two alpha subdivision bacteria, R. meliloti and C. crescentus, CcrM-mediated methylation has important cellular functions. In both organisms, CcrM is essential for viability. Overexpression of CcrM in either bacterium results in defects in cell division and cell morphology and in the initiation of DNA replication. Finally, the C. crescentus and R. meliloti ccrM genes are functionally interchangeable, as the complemented strains are viable and the chromosomes are methylated. Thus, in both R. meliloti and C. crescentus, CcrM methylation is an integral component of the cell cycle. We speculate that CcrM-mediated DNA methylation is likely to have similar roles among alpha subdivision bacteria.

An economic analysis of the Survival and Ventricular Enlargement (SAVE) Study. Application to the United Kingdom

Recent studies have shown that ACE inhibitors reduce morbidity and mortality after myocardial infarction (MI). While these trials have obvious clinical implications, the widespread introduction of a new treatment for a condition as common as MI also has clear cost implications. The results of the post-MI studies with ACE inhibitors suggest that restricted use of treatment-in high-risk patients-is likely to be most cost effective, whereas treatment of all MI survivors, many of whom are at low risk, will be least cost effective. An approach somewhere in between may maximise clinical benefit at an acceptable cost. Economic analysis may help in deciding how these drugs might be best used after MI. We have conducted a cost-effectiveness and cost-utility analysis of the Survival and Ventricular Enlargement (SAVE) study, which reported the benefit of ACE inhibitors in intermediate-risk patients. Assuming all MI survivors require measurement of left ventricular function before selection for treatment (the approach used in the SAVE study), the incremental cost per life-year gained (LYG), over 4 years, using prophylactic captopril is approximately 10000 pounds sterling (Pounds) [1994 to 1995 values]. The cost per quality-adjusted life-year (QALY) is similar. These incremental cost per LYG and cost per QALY ratios compare favourably with other commonly used symptomatic and prophylactic treatments, and argue for extending post-MI use of ACE inhibitors to intermediate-as well as high-risk patients.

Congenital lymphocytic choriomeningitis virus syndrome: a disease that mimics congenital toxoplasmosis or Cytomegalovirus infection

OBJECTIVE

To describe the clinical characteristics of intrauterine infection with lymphocytic choriomeningitis (LCM) virus, an uncommonly recognized cause of congenital viral infection.

PATIENTS

Three infants born in the midwestern United States in 1994 and 1995 with clinical features and serologic studies consistent with congenital LCM virus infection and cases of congenital infection identified by review of the medical literature between 1955 and 1996.

RESULTS

Twenty-six infants with serologically confirmed congenital LCM virus infection were identified. Twenty-two infants were products of term gestations, and birth weights ranged from 2384 to 4400 g (median, 3520 g). Ocular abnormalities, macrocephaly, or microcephaly were the most commonly identified neonatal features. Twenty-one infants (88%) had chorioretinopathy, 10 (43%) had macrocephaly (head circumference >90th percentile) at birth, and 3 (13%) were microcephalic (head circumference <10th percentile). Macrocephaly and hydrocephalus developed postnatally in one of the latter infants. Hydrocephalus or intracranial calcifications were documented in five infants by computed tomography or magnetic resonance imaging. Nine infants (35%) died, and 10 (63%) of the 16 reported survivors had severe neurologic sequelae, consisting of spastic quadriparesis, seizures, visual loss, or mental retardation. One-half of the mothers reported illnesses compatible with LCM virus infection, and 25% reported exposures to rodents during their pregnancies.

CONCLUSIONS

These cases suggest that congenital LCM virus infection could be an underrecognized cause of congenital infection among infants born in the United States. Because of the clinical similarities of these congenital infections, cases of congenital LCM virus infection can be confused with infections with cytomegalovirus or Toxoplasma gondii.

Monozygotic twins discordant for schizophrenia are discordant for N-CAM and L1 in CSF

While schizophrenia has a genetic component, its pathogenesis is unknown. Abnormal concentrations of two cell recognition molecules (CRMs), neural-cell adhesion molecule (N-CAM) and L1 antigen have been described in the cerebrospinal fluid (CSF) of patients with schizophrenia. Studies of monozygotic twins discordant for schizophrenia may help separate genetic and environmental contributions to the disease. In the present study of monozygotic twins discordant for schizophrenia, the affected twins had increased N-CAM and decreased L1 antigen in their CSF. Non-affected twins were not different from normals. Although processes related to genetic instability cannot be entirely ruled out, these results suggest that these abnormalities are not a part of the genetic predisposition to become schizophrenic. Thus the changes in N-CAM and L1 antigen may reflect either the events which precipitated the onset of schizophrenia, or events which are associated with the experience of having the disease.

Videofluoroscopic evaluation of dysphagia in motor neurone disease with modified barium swallow

The role of videofluoroscopy with the modified barium swallow in the assessment and management of motor neurone disease (MND) is discussed. Nine patients (age range 40-82) with dysphagia secondary to MND were assessed over a four-year period. The examinations were carried out by a multiprofessional team of radiologist, speech and language therapist and dietitian assessing the preoral, oral and pharyngeal phases of swallowing. Preoral feeding abnormalities were present in four out of nine patients, oral phase abnormalities in eight out of nine patients, while 33% of patients demonstrated abnormality in all three phases. Where aspiration occurred (four out of nine cases), no cough reflex was noted. On the basis of these examinations management changes were introduced in all patients. Nonoral feeding was continued or introduced in three patients. Videofluoroscopic examination with the modified barium swallow may be helpful in planning suitable feeding regimes for dysphagia in MND.

Quantitative trait loci contributing to phencyclidine-induced and amphetamine-induced locomotor behavior in inbred mice

Phencyclidine (PCP) and amphetamine (AMP) can induce psychotic syndromes in humans, whereas administration of these drugs to mice results in behavioral activation that is influenced by genetic factors. Quantitative trait loci (QTL) underlying genetic differences in response to PCP and AMP in mice were provisionally identified by correlating allelic variation at known marker loci in the BXD series of recombinant inbred (RI) mice and its progenitors (C57BL/6J and DBA/2J inbred strains) with the locomotor response of each strain to PCP and AMP. Total distance traveled for individual mice from each of the 26 BXD RI and two progenitor strains was measured after injections of normal saline and 7.5 mg/kg i.p. injection of PCP. This procedure was repeated after 1 week, using 5.0 mg/kg of AMP, instead of PCP. Markers significantly (p < .01) correlated with response to PCP map to murine chromosomes 1, 14, and 15. Response to amphetamine was correlated with markers mapping to chromosomes 4, 5, 6, 8, 14, and 18. Identification of the QTL underlying PCP-induced and AMP-induced behavior in mice may provide clues into the complicated genetics of psychosis in humans.

Perception of direction of visual motion. II. Influence of linear body acceleration

We investigated whether linear whole-body acceleration along the interaural y-axis influenced the concurrent perception of visual motion direction as has been shown for angular accelerations. A sled running on air bearings along a 7.5-m track was used to accelerate 18 subjects at two different linear accelerations. These young, healthy volunteers, aged 25.50 +/- 7.38 years, used a joystick to indicate whether or not they perceived visual motion to the left within a random-dot kinematogram continuously presented on a monitor moving with them. The percentage of coherently leftward moving pixels presented for a 640-ms period during acceleration was adjusted according to a Modified Binary Search (MOBS) procedure. Six conditions were tested, two acceleration levels of 1 and 2 m/s2 to both left and right with, at the higher acceleration, two different times of visual motion presentation. Conditions were sequenced by means of a 6 x 6 Latin square balanced for order and carry over. A MANOVA did not show any statistically significant effects either for the independent variables acceleration, velocity, and direction of motion of the sled or for their interactions. The results obtained are in clear contrast to those obtained under rotatory stimulation. We conclude that the otolithic contribution to vestibular-visual motion processing is negligible.

Molecular, functional and evolutionary characterization of the gene encoding HMG-CoA reductase in the fission yeast, Schizosaccharomyces pombe

The synthesis of mevalonate, a molecule required for both sterol and isoprene biosynthesis in eukaryotes, is catalysed by 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Using a gene dosage approach, we have isolated the gene encoding HMG-CoA reductase hmgl+, from the fission yeast Schizosaccharomyces pombe (Accession Number L76979). Specifically, hmgl+ was isolated on the basis of its ability to confer resistance to lovastatin, a competitive inhibitor of HMG-CoA reductase. Gene disruption analysis showed that hmgl+ was an essential gene. This result provided evidence that, unlike Saccharomyces cerevisiae, S. pombe contained only a single functional HMG-CoA reductase gene. The presence of a single HMG-CoA reductase gene was confirmed by genomic hybridization analysis. As observed for the S. cerevisiae HMGlp, the hmgl+ protein induced membrane proliferations known as karmellae. A previously undescribed 'feed-forward' regulation was observed in which elevated levels of HMG-CoA synthase, the enzyme catalysing the synthesis of the HMG-CoA reductase substrate, induced elevated levels of hmgl+ protein in the cell and conferred partial resistance to lovastatin. The amino acid sequences of yeast and human HMG-CoA reductase were highly divergent in the membrane domains, but were extensively conserved in the catalytic domains. We tested whether the gene duplication that produced the two functional genes in S. cerevisiae occurred before or after S. pombe and S. cerevisiae diverged by comparing the log likelihoods of trees specified by these hypotheses. We found that the tree specifying post-divergence duplication had significantly higher likelihood. Moreover, phylogenetic analyses of available HMG-CoA reductase sequences also suggested that the lineages of S. pombe and S. cerevisiae diverged approximately 420 million years ago but that the duplication event that produced two HMG-CoA reductase genes in the budding yeast occurred only approximately 56 million years ago. To date, S. pombe is the only unicellular eukaryote that has been found to contain a single HMG-CoA reductase gene. Consequently, S. pombe may provide important opportunities to study aspects of the regulation of sterol biosynthesis that have been difficult to address in other organisms and serve as a test organism to identify novel therapies for modulating cholesterol synthesis.