The mental health impact of contact with COVID-19 patients on healthcare workers in the United States

This study assessed the relationship between contact with COVID-19 patients and the mental health of healthcare workers (HCWs) in the United States (US). In a convenience sample of 957 HCWs who completed an anonymous online survey between April-May 2020, HCWs who provided direct care to confirmed or suspected COVID-19 patients reported increased depressive and posttraumatic symptoms compared to HCWs with no COVID-19 patient contact. Additionally, more frequent contact was associated with higher distress. More data drawn from diverse samples that better represent US HCWs are needed to fully assess the scope of this association.

Genital tract infections in HIV-infected pregnant women in South West London

There are minimal UK data on the prevalence of genital tract infections in HIV‐infected pregnant women. British HIV Association guidelines suggest sexually transmitted infection (STI) screening as early as possible in pregnancy with consideration given to repeat at 28 weeks’ gestation. A retrospective case notes review of HIV-infected pregnant women at four South London HIV Centres (1 January 2004–1 January 2014) was carried out. Five hundred and ninety-eight pregnancies in 384 patients were identified. Median age 32 years (interquartile range [IQR] 27–36) and 96% (n = 346) were heterosexually infected. HIV was diagnosed antenatally in 21% of pregnancies (n = 107). Seventy-seven per cent of women (n = 384) were of Black African ethnicity and 75% were born in sub-Saharan Africa with 14% UK-born. The majority of pregnancies (279/507) were reported to be unplanned with 42 women proceeding to termination of pregnancy. A regular male partner was reported in 95% of pregnancies (n = 539) with median relationship duration (n = 347) of four years (IQR 1.5–7.0); 11/324 (3.4%) women reported additional sexual partners during the pregnancy. 76.6% (n = 427) of women had an initial STI screen which was done in the first trimester in 52.1%; 32.1% of women had a repeat STI screen in pregnancy, 96% of which was done in the third trimester. Overall, 61 (14.3%) women were diagnosed with at least one STI during their pregnancy. Vaginal candidiasis and bacterial vaginosis were diagnosed in 27.6% (n = 100) and 21.7% (n = 73) of pregnancies, respectively. STI prevalence was low and obstetric outcomes favourable in this cohort of women. Further information about STI prevalence in this population may impact future screening guidelines.

Lopinavir and atazanavir in pregnancy: comparable infant outcomes, virological efficacies and preterm delivery rates

OBJECTIVES

The aim of the study was to identify differences in infant outcomes, virological efficacy, and preterm delivery (PTD) outcome between women exposed to lopinavir/ritonavir (LPV/r) and those exposed to atazanavir/ritonavir (ATV/r).

METHODS

A retrospective case note review was carried out. The case notes of 493 women who conceived while on LPV/r or ATV/r or initiated LPV/r or ATV/r during pregnancy and who delivered between 1 September 2007 and 30 August 2012 were reviewed. Data collected included demographics, antiretroviral use, HIV markers, and pregnancy and infant outcomes. Infant outcomes, virological efficacies and PTD rates for LPV/r and ATV/r were compared.

RESULTS

A total of 306 women received LPV/r (82 conceiving while on the drug and 224 commencing it post-conception) and 187 received ATV/r (96 conceiving while on the drug and 91 commencing it post-conception). Comparing the two protease inhibitors (PIs), viral suppression rates were similar and, in women starting antiretroviral therapy (ART) post-conception, the median times to first undetectable HIV viral load were not significantly different (P = 0.64). PTD rates did not differ by therapy overall (ATV/r, 13%; LPV/r, 14%) or when considering the timing of first exposure (conceiving on ART, P = 0.81; commencing ART in pregnancy, P = 0.08). Poor fetal outcomes were very uncommon. There were two transmissions, giving a mother-to-child transmission (MTCT) rate of 0.4% (95% confidence interval 0.05-1.5%).

CONCLUSIONS

Both ART regimens were well tolerated and successful in preventing MTCT. No significant differences in tolerability or in pregnancy or infant outcomes were observed, which supports the provision of a choice of PI in pregnancy.

Duplication 5q and deletion 9p due to a t(5;9)(q34;p23) in 2 cousins with features of Hunter-McAlpine syndrome and hypothyroidism

We report on 2 similarly affected cousins with a compound imbalance resulting from a familial t(5;9)(q34;p23) and entailing both an ∼17-Mb 5q terminal duplication and an ∼12-Mb 9p terminal deletion as determined by G-banding, subtelomere FISH, and aCGH. The proband's karyotype was 46,XX,der(9)t(5;9)(q34;p23)mat.ish der(9)t(5;9)(q34;p23)(9pter-,5qter+).arr 5q34q35(163,328,000-180,629,000)×3, 9p24p23(194,000-12,664,000)×1. Her cousin had the same unbalanced karyotype inherited from his father. The clinical phenotype mainly consists of a distinct craniofacial dysmorphism featuring microcephaly, flat facies, down slanting palpebral fissures, small flat nose, long philtrum, and small mouth with thin upper lip. Additional remarkable findings were craniosynostosis of several sutures, craniolacunia and preaxial polydactyly in the proband and hypothyroidism in both subjects. The observed clinical constellation generally fits the phenotypic spectrum of the 5q distal duplication syndrome (known also as Hunter-McAlpine syndrome), except for the thyroid insufficiency which can likely be ascribed to the concurrent 9p deletion, as at least 4 other 9pter monosomic patients without chromosome 5 involvement had this hormonal disorder. The present observation further confirms the etiology of the HMS phenotype from gain of the 5q35→qter region, expands the clinical pictures of partial trisomy 5q and monosomy 9p, and provides a comprehensive list of 160 patients with 5q distal duplication.

A randomized, placebo-controlled trial of repeated IV antibiotic therapy for Lyme encephalopathy

BACKGROUND

Optimal treatment remains uncertain for patients with cognitive impairment that persists or returns after standard IV antibiotic therapy for Lyme disease.

METHODS

Patients had well-documented Lyme disease, with at least 3 weeks of prior IV antibiotics, current positive IgG Western blot, and objective memory impairment. Healthy individuals served as controls for practice effects. Patients were randomly assigned to 10 weeks of double-masked treatment with IV ceftriaxone or IV placebo and then no antibiotic therapy. The primary outcome was neurocognitive performance at week 12-specifically, memory. Durability of benefit was evaluated at week 24. Group differences were estimated according to longitudinal mixed-effects models.

RESULTS

After screening 3368 patients and 305 volunteers, 37 patients and 20 healthy individuals enrolled. Enrolled patients had mild to moderate cognitive impairment and marked levels of fatigue, pain, and impaired physical functioning. Across six cognitive domains, a significant treatment-by-time interaction favored the antibiotic-treated group at week 12. The improvement was generalized (not specific to domain) and moderate in magnitude, but it was not sustained to week 24. On secondary outcome, patients with more severe fatigue, pain, and impaired physical functioning who received antibiotics were improved at week 12, and this was sustained to week 24 for pain and physical functioning. Adverse events from either the study medication or the PICC line were noted among 6 of 23 (26.1%) patients given IV ceftriaxone and among 1 of 14 (7.1%) patients given IV placebo; these resolved without permanent injury.

CONCLUSION

IV ceftriaxone therapy results in short-term cognitive improvement for patients with posttreatment Lyme encephalopathy, but relapse in cognition occurs after the antibiotic is discontinued. Treatment strategies that result in sustained cognitive improvement are needed.

Estradiol and orexin-2 saporin actions on multiple forms of behavioral arousal in female mice

Estrogens modulate almost all aspects of female behavioral arousal; however, apart from that of sexual behavior, the neurobiology of female arousal remains unclear. Because orexins-hypocretins are neurotransmitters known to be important for behavioral arousal, the authors hypothesized that orexins may be a target for estrogen. Gonadectomized female mice received an intracerebral injection of either phosphate-buffered saline, the neurotoxin saporin (SAP), or the orexin-2-saporin conjugate (OXSAP) in the lateral hypothalamus. SAP- and OXSAP-treated mice were also divided into groups receiving either estradiol capsules or oil capsules. Mice were tested in 3 behavioral tests measuring different modes of arousal: sensory responsiveness, running wheel activity, and fearfulness. OXSAP mice showed decreases in sensory responsiveness and fearfulness concomitant with a reduction in orexin cell number. Estradiol affected all behaviors tested but decreased fearfulness only when combined with OXSAP treatment. These data indicate that estrogens modulate orexins' effects on fearfulness.

Gender-related differences in thrombogenic factors predicting recurrent cardiac events in patients after acute myocardial infarction. The THROMBO Investigators

Thrombosis contributes to recurrent coronary events in patients after acute myocardial infarction (AMI), but prognostic significance of thrombogenic factors by gender is unknown. This study aimed to determine gender-related differences in the prognostic significance of thrombogenic factors for predicting cardiac events (nonfatal reinfarction or cardiac death) in postinfarction patients. Blood levels of the following factors were measured 2 months after AMI in 791 men and 254 women: fibrinogen, von Willebrand factor, factor VII and VIIa, plasminogen activator inhibitor, D-dimer, cholesterol, apolipoprotein A-1, apolipoprotein B, lipoprotein(a), triglycerides, and high-density lipoprotein cholesterol. After adjustment for clinical covariates, levels of apolipoprotein A, high-density lipoprotein cholesterol, fibrinogen, and factor VIIa were significantly higher in postinfarction women than men. During a mean 26-month follow-up, there were 67 cardiac events (8.5%) in men and 14 (5.5%) in women (p = 0.11). In the multivariate Cox model, elevated levels of factor VIIa were a significant predictor of cardiac events in women (p = 0.022) but not in men (p = 0.80), with significant gender-related effect (hazard ratio 2.80 vs 0.92, respectively; p <0.05). D-dimer had prognostic value in men (p = 0. 006) but not in women (p = 0.36), although the difference between hazard ratios for men and women was not significant (2.35 vs 1.58, respectively; p = 0.49). In conclusion, elevated levels of factor VIIa are associated with an increased risk of recurrent cardiac events in postinfarction women, but not in men. D-dimer is more predictive for cardiac events in postinfarction men than women. These observations indicate possible gender-related differences in the pathophysiologic mechanisms of recurrent cardiac events.

Ultrasound as a screening study for gastro-oesophageal reflux in children

A comparison of the abilities of ultrasound and scintigraphy to detect gastro-oesophageal reflux was made in 110 children (mean age 24.5 months) who were divided into groups A (n = 49) and B (n = 61). The former had scintigraphy first followed by ultrasound within about 30 min. For group B scintigraphy was also performed first, but the delay before ultrasound ranged between 1 and 30 days. In most patients (91/110) concordant results were obtained by the two modalities. The 19/110 discordant results can be explained by several plausible mechanisms. It is concluded that ultrasound should be employed much more frequently as an initial investigation when pathological reflux is suspected in children.

Pegylated megakaryocyte growth and development factor abrogates the lethal thrombocytopenia associated with carboplatin and irradiation in mice

Megakaryocyte growth and development factor (MGDF) is a potent inducer of megakaryopoiesis in vitro and thrombopoiesis in vivo. The effects of MGDF appear to be lineage-selective, making this cytokine an ideal candidate for use in alleviating clinically relevant thrombocytopenias. This report describes a murine model of life-threatening thrombocytopenia that results from the combination treatment of carboplatin and sublethal irradiation. Mortality of this regimen is 94% and is associated with widespread internal bleeding. The daily administration of pegylated recombinant human MGDF (PEG-rMGDF) significantly reduced mortality (to < 15%) and ameliorated the depth and duration of thrombocytopenia. The severity of leucopenia and anemia was also reduced, although it was not clear whether these effects were direct. Platelets generated in response to PEG-rMGDF were morphologically indistinguishable from normal platelets. PEG-rMGDF administered in combination with murine granulocyte colony-stimulating factor completely prevented mortality and further reduced leukopenia and thrombocytopenia. These data support the concept that PEG-rMGDF may be useful to treat iatrogenic thrombocytopenias.

The role of the trimolecular complex (alpha beta TCR-MHC+peptide) in the pathogenesis of systemic sclerosis

Systemic sclerosis is an intricate disease process whose most unique and specific parameter indicative of autoimmunity is the presence of autoantibodies directed against certain nuclear antigens. The relationship between this particular humoral immune response and the genesis of a fibrotic tissue response in the skin as well as internal organs is not yet well understood. The prominence of CD4 T-cell infiltration during early phases of disease suggest that activation pathways may be initiated which subsequently result in phenotypic changes of a variety of mesenchymal cells, especially endothelial cells and fibroblasts. Taken in concert with the association of susceptibility with certain MHC class II molecules, the conventional presenters of exogenous peptide to T cells of the CD4 lineage, the notion of a central critical immune recognition event underlying the development of systemic sclerosis gains increasing likelihood. In addition to the still incompletely understood paracrine pathways between immune response and fibrosis, there is a nearly complete void of knowledge concerning what peptide is recognized by the T-cell and the structure of the alpha beta TCR involved in this recognition. Determining the role of the alpha beta TCR in the activation of the T-cell population in terms of identifying structural features which are critical participants in this process and the functional derangement leading to the characteristic pattern of self recognition will certainly enhance our understanding of the pathogenesis of systemic sclerosis.

Grouping HLA-B locus serologic specificities according to shared structural motifs suggests that different peptide-anchoring pockets may have contrasting influences on the course of HIV-1 infection

Two different groups of HLA-B specificities were associated with two contrasting outcomes of HIV-1 infection. HLA-B45, -B49, and -B50 were each found at a moderately increased frequency among individuals responding to HIV-1 infection with a marked circulating and infiltrative CD8 T-cell lymphocytosis, a slow rate of CD4 T-cell decline, very low frequency of opportunistic infections, and low viral strain heterogeneity. In contrast, among HIV-infected individuals with more rapid progression to opportunistic infections, HLA-B35 was found to be increased in frequency and to act as a dominant marker for this adverse outcome. HLA-B45, -B49, and -B50 contain identical peptide-anchoring "B" and "C-terminal" pocket structures, which differ greatly from those present in HLA-B35, implying that different immunogenic peptides are likely to be bound by these two groups of alleles. Placing HLA-B45, -B49, and -B50 into one structurally defined group revealed a much stronger and statistically significant association with the CD8 lymphocytosis syndrome (OR = 5.3, p = 0.0005). The B pocket structure in these alleles contains an easily accessible lysine residue at position 45, suggesting that the P2 or P3 anchor residue of a bound peptide is negatively charged. Additionally, by observing the effect on the ORs of adding structures containing amino acid substitutions in the C-terminal pocket of HLA-B45, -B49, and -B50, this region was also shown to influence susceptibility to this host response.(ABSTRACT TRUNCATED AT 250 WORDS)

Certain HLA-DR5 and -DR6 major histocompatibility complex class II alleles are associated with a CD8 lymphocytic host response to human immunodeficiency virus type 1 characterized by low lymphocyte viral strain heterogeneity and slow disease progression

Either of two structurally related major histocompatibility complex class II alleles, DRB1*1102, which encodes a DR5 specificity, or DRB1*1301, which encodes a DR6 specificity, was found in 67% of individuals responding to human immunodeficiency virus type 1 (HIV-1) infection with a syndrome characterized by persistent circulating and diffusely infiltrative CD8 lymphocytosis (DILS), slow progression to opportunistic infections, and delayed CD4 T-cell depletion. These alleles were present in only 28% of ethnically matched HIV-positive controls (P = 0.001). The frequency of DRB1*1301 was increased in both Blacks and Caucasians with this syndrome, while that of DRBI*1102 was increased only in Blacks, where 80% had either of these alleles. To investigate whether the host response associated with these alleles influences the evolutionary divergence of the HIV-1 genome, sequencing of the envelope V3 loop was performed. This revealed a significantly diminished lymphocyte viral heterogeneity compared with random HIV+ controls matched for CD4 T-cell levels. These results suggest that the immunogenetics of the host influence the nature of the immune response to HIV-1, which may lead to constrained evolution of HIV-1 gene products. Of possible relevance, the alpha-helical third diversity region common to both the DRB1*1102 and DRB1*1301 allelic products was noted to have homology with the C-terminal region of the HIV-1 envelope V3 loop at six of nine consecutive residues. This suggests the possibility that these alleles may bias the anti-HIV T-cell receptor repertoire through a mimicry mechanism.

Sustained and distinctive patterns of gene activation in synovial fibroblasts and whole synovial tissue obtained from inflammatory synovitis

Fibroblastoid synovial lining cells isolated from rheumatoid and other chronic inflammatory synovial tissue exhibit distinctive and sustained alterations in serial culture not commonly found in similarly cultured cells from osteoarthritic synovium. These are demonstrable using a multi-gene dot blot assay by labelling reverse transcribed fibroblast cDNA which is hybridized to plasmids containing relevant target gene inserts. Cultured synovial fibroblastoid cells from patients with chronic inflammatory synovitis expressed significantly higher levels of stromelysin, vimentin and TIMP-1 mRNA and lower levels of c-myc compared to cells isolated from osteoarthritis synovium although with considerable variation. Early fetal synovial lining cells were similar to cells from osteoarthritis synovium but vimentin expression was higher. Marked differences in patterns of gene expression between cell lines persisted through 10 serial passages over 6-8 months. In whole synovia, the average level of mRNA for stromelysin, vimentin, IL-4, IL-6, TIMP-1, cathepsin D, gelatinase, TGF alpha, c-fms and DR beta were preferentially expressed in inflammatory tissue while c-myc expression was higher in osteoarthritis synovium. Inflammatory synovium also expressed TNF alpha, IL-1 alpha, IL-1 beta, IL-2, c-sis, tissue plasminogen activator, CSF-1, and GM-CSF. This pattern resembles, in part, that found in cultured inflammatory fibroblasts but, in addition, gene products apparently reflecting the presence of activated monocytes and lymphocytes were detected. These results provide evidence that profiles of certain gene activation in cells from patients with inflammatory synovitis differ from those with non-inflammatory disease and suggest that the fibroblastoid cells are responsible for a considerable proportion of the altered phenotypic expression pattern in whole tissue. Furthermore, this modulated pattern of gene activation appears to be an intrinsic pro-inflammatory characteristic of the fibroblastoid cells initiated in response to chronic inflammation and persists for a prolonged period in the absence of other inflammatory cells.

Characterization of the primary structure of T cell receptor beta chains in cells infiltrating the salivary gland in the sicca syndrome of HIV-1 infection. Evidence of antigen-driven clonal selection suggested by restricted combinations of V beta J beta gene segment usage and shared somatically encoded amino acid residues

Infection with HIV-1 occasionally results in a sicca syndrome, termed the diffuse infiltrative lymphocytosis syndrome, characterized by infiltration of the salivary glands with a predominance of CD8 T cells. This response is strongly associated with certain MHC class I and class II alleles. To define the salivary gland T cell receptor (TCR) repertoire, the primary structure of the TCR beta-chains was determined using in situ cDNA synthesis followed by the "anchored" polymerase chain reaction. The sequences of 59 beta-chains from five individuals with diffuse infiltrative lymphocytosis syndrome shared structural features suggesting antigenic clonal selection. Certain combinations of V beta J beta gene segments were selectively overrepresented in the repertoire sample, demonstrating a common restricted usage of certain V beta and J beta gene segments. The beta-chains derived from these overrepresented V beta J beta combinations revealed a preference for specific amino acids at position 97 in the third complementarity-determining region, a residue postulated to contact peptide antigen. Moreover, the nucleotides encoding this position were not germline in origin. TCR beta-chains in nonoverrepresented V beta J beta combinations did not exhibit preferential usage of selected somatically encoded residues. The pattern of TCR beta-chains expressed in the salivary gland of a control person with primary Sjögren's syndrome was considerably more heterogeneous and different from that found in diffuse infiltrative lymphocytosis syndrome.

Association of chronic Lyme arthritis with HLA-DR4 and HLA-DR2 alleles

BACKGROUND AND METHODS

A small percentage of patients infected with Borrelia burgdorferi have chronic Lyme arthritis that does not respond to antibiotic therapy. To learn whether genetically determined variations in the host immune response might account for such outcomes, we determined the immunogenetic profiles of 130 patients with various manifestations of Lyme disease.

RESULTS

Of the 80 patients with arthritis, 57 percent of those with chronic arthritis (12 to 48 months in duration) had the HLA-DR4 specificity; only 23 percent of those with arthritis of moderate duration (6 to 11 months) and only 9 percent of those with arthritis of short duration (1 to 5 months) had this specificity (P = 0.003). After the HLA-DR4-positive patients were excluded from each group, a secondary association was noted with HLA-DR2, which was found in 75 percent of the remaining patients with chronic arthritis and in 50 percent of those with arthritis of moderate duration, but in only 20 percent of those with arthritis of short duration (P = 0.023). Altogether, 25 of the 28 patients with chronic arthritis (89 percent) had HLA-DR2 or HLA-DR4, or both, as compared with 27 percent of those with arthritis of short duration (relative risk, 22; P = 0.00006). These HLA specificities appeared to act as independent, dominant markers of susceptibility. Nucleotide-sequence typing, performed in five patients with chronic arthritis, identified the HLA-DR2 allele as Dw2 (DR beta 1*1501), and the HLA-DR4 alleles as Dw4, Dw14, and Dw13 (DR beta 1*0401, DR beta 1*0404, and DR beta 1*0403, respectively). The presence of HLA-DR4 in patients with arthritis was associated with a lack of response to antibiotic therapy (P = 0.01).

CONCLUSIONS

Particular Class II major histocompatibility genes determine a host immune response to B. burgdorferi that results in chronic arthritis and lack of response to antibiotic therapy.

A pilot study of paramedic-administered, prehospital thrombolysis for acute myocardial infarction

We have implemented a pilot program of supervised paramedic administration of thrombolysis in the field. This program was begun on a small scale by training and equipping one paramedic service of one hospital. Four patients with acute myocardial infarction were rapidly and appropriately treated in the field. We compared these 4 patients with 21 patients who were brought to hospital by ambulance, but treated with thrombolysis conventionally in the emergency department. The patients in the field were treated an average of 86 minutes sooner than the patients treated in the emergency department.

Definition of DRw10 by restriction fragment length polymorphism

To better define the presence of the DRw10 haplotype which has sometimes proved difficult to type by using serologic reagents, Southern blot analysis was performed on seven DRw10 heterozygous individuals with rheumatoid arthritis. Using the restriction enzymes Taq I or BamH I, the restriction fragment length polymorphism (RFLP) pattern for the DRw10 haplotype was clearly distinguishable from that of other DR alleles. Digestion with Taq I revealed a unique DR beta/Taq I 12.20 fragment. A characteristic DR beta/Taq I 4.60 fragment was also present only in DRw10 and DR1 haplotypes. Digestion with the restriction enzyme BamH I revealed a DR beta/BamH I 5.07 fragment also present in DRw10 and DR1 haplotypes, and a DR beta/BamH I 4.30 fragment shared with the DRw52 and DR2 haplotypes but not found in DR1 haplotypes. The pattern was readily distinguished from those given by the haplotypes DR4, 7 and w9. Family studies of five individuals demonstrated appropriate segregation of the restriction fragments. In particular, segregation of DRw10 haplotypes from DR1 haplotypes was clearly shown in a family in which the DRw10 haplotype was associated with rheumatoid arthritis in two individuals. Southern blot analysis proved to be a useful alternative method for identifying the DRw10 allele in certain combinations where this allele has been difficult to define serologically.

Oral disopyramide therapy for obstructive hypertrophic cardiomyopathy

Seven patients with obstructive hypertrophic cardiomyopathy (HC) were treated with oral disopyramide. Left ventricular outflow tract gradients were estimated using either Doppler or M-mode echocardiography. Gradients were measured before treatment, after acute and chronic dosing, after washout and after rechallenge. Disopyramide serum levels were measured at the time of echocardiography. With the first dose, mean outflow gradient decreased from 64 to 14 mm Hg (p less than 0.0001). This decrease in gradient was still present after long-term oral treatment 23 days later, with a mean gradient of 13 mm Hg (p less than 0.001). After withdrawal from the drug, gradient returned to the pretreatment value, 79 mm Hg. After rechallenge, the gradient once again declined to 30 mm Hg (p less than 0.001). High disopyramide serum levels correlated with lower outflow tract gradients, r = -0.77 (p less than 0.0001). Even at low therapeutic drug levels, there was a 49% reduction in outflow tract gradient. Four patients were symptomatically improved and have been maintained on disopyramide for greater than 1 year. In symptomatic patients, disopyramide acutely decreases obstruction and also provides sustained pharmacologic control of obstruction. Disopyramide should be considered as a good alternative to treatment with adrenergic blockers, calcium antagonists or surgery.

Hypotheses on the molecular basis of susceptibility to rheumatoid arthritis

An interpretive summary of recent immunologic and molecular biologic data concerning the molecular basis of susceptibility of rheumatoid arthritis will be presented. The central point of view is taken that the MHC class II molecules encoding disease susceptibility function in a specific immune recognition event. This could involve an antigen "X" that currently eludes characterization or be directed to polymorphic determinants on the MHC molecule itself. The problem of understanding the meaning of the association of susceptibility to rheumatoid arthritis with diverse MHC alleles such as DR4 (Dw4 and Dw14) and DR1 is approached by detailed biochemical analysis that led to the identification of common stretches of amino acid sequence, presumably encoding conformationally equivalent structures. The sequence shared by the otherwise unrelated DR1 and DR4 haplotypes from residue 67 in the DR a chain that appears to confer susceptibility is Leu-X-X-Gln-Arg/Lys. Non-classic MHC polymorphisms related to disease susceptibility but not associated with particular alleles such as identified by Ab109d6 prove especially valuable in suggesting new directions for attempting to understand the significance of these associations. Consideration is given to the possibility that a family of either slightly different or identical conformations encoded in either cis or trans cumulatively confer the liability to develop rheumatoid arthritis. This implies a highly non-classic mode of inheritance. It seems reasonable to consider the pathogenesis of rheumatoid arthritis as evolving from a typical immune response based on a simple immune recognition event directed to a single antigen.

Metabolic derangements in children requiring parenteral nutrition

Intravenous alimentation is routinely used in many hospitalized pediatric patients, however, there are few reports of the nature and frequency of metabolic complications. In order to assess the frequency and nature of metabolic complications all children receiving parenteral nutrition from January 1, 1982 to December 31, 1982 were prospectively enrolled in the study. Data collection began with the institution of parenteral nutrition. Serum electrolytes, minerals, liver function tests, and renal function tests were followed weekly. A total of 201 patients received parenteral nutrition for 5378 days. Nutrition was delivered to 146 patients (4980 patient days) via a central line and 55 patients via a peripheral line (398 patient days). The sepsis rate was 3.7% in central lines used only for parenteral and 4.8% in multipurpose central lines. In general, complications were fewer in the patients supported peripherally. In patients supported centrally, hypoalbuminemia was the most commonly found abnormality followed by hypocalcemia, hypophosphatemia and hypomagnesemia, reflecting a malnourished state. One-third of the patients had abnormal liver function tests, and in half of those factors causing liver dysfunction other than parenteral nutrition were present. Abnormal renal function tests occurred in 10% of the patients. Thus, a high incidence of metabolic complications occurred in association with parenteral nutrition. Most were present during the initiation of parenteral nutrition, suggesting an abnormal metabolic state was present prior to the institution of parenteral nutrition. The frequency of low serum albumin and minerals is consistent with previous publications of the prevalence of malnutrition in hospitalized patients.