1363. Moving from Public Health Outbreak Response to Mitigation for a Regional Outbreak of Highly-Resistant New Delhi Metallo-β-Lactamase-Producing Acinetobacter baumannii in California, May 2020 – April 2022

Background

Since May 2020, the California Department of Public Health and 12 local health jurisdictions (LHJ) have responded to a regional outbreak of highly-resistant New Delhi metallo-β-lactamase-producing Acinetobacter baumannii (NDM AB). Starting in October 2021, public health shifted from outbreak response to resource-conscious long-term mitigation in affected healthcare facilities, and prevention of spread to interconnected facilities.

Methods

We defined a case as a patient identified with an NDM AB clinical isolate, or NDM positive colonization screening and epidemiologic linkage. In October 2021, we lengthened the screening interval and changed the screening population in outbreak skilled nursing facilities (SNF) and long-term acute care hospitals to only include high-risk patients (total dependence for activities of daily living, having wounds or indwelling devices, or ventilated); we continued to screen ventilator units in ventilator-equipped SNF, and epidemiologically-linked unit(s) in acute care hospitals. Concurrently, public health initiated a prevention collaborative focused on improving environmental services (EVS) practices in the most affected LHJ, including 3 outbreak and 4 non-outbreak SNF to promote sustainable EVS practice improvement and peer-to-peer learning.

Results

Whereas we identified 170 cases during the outbreak response period May 2020 – September 2021, since October 2021 we identified only 43 cases. Screening test percent positivity decreased from 3.0% (105/3542) through September 2021 to 1.4% (21/1505) since October 2021. During the outbreak response period, we completed 42 infection prevention and control (IPC) onsite assessments that identified poor adherence to core EVS practices; since October 2021, we completed 29 assessments, including 14 for the EVS prevention collaborative.

Conclusion

Long-term mitigation of regional, multifacility novel multidrug-resistant organism outbreaks is possible by implementing a coordinated package of interventions including proactive targeted IPC assessment and support at interconnected facilities, and continued routine public health follow-up at outbreak facilities.

Disclosures

All Authors: No reported disclosures.

Ecogenomics and metabolic potential of the South Atlantic Ocean microbiome

The unique combination of depth, salinity, and water masses make the South Atlantic Ocean an ecosystem of special relevance within the global ocean. Yet, the microbiome of this ecosystem has received less attention than other regions of the global Ocean. This has hampered our understanding of the diversity and metabolic potential of the microorganisms that dwell in this habitat. To fill this knowledge gap, we analyzed a collection of 31 metagenomes from the Atlantic Ocean that spanned the epipelagic, mesopelagic and bathypelagic zones (surface to 4000 m). Read-centric and gene-centric analysis revealed the unique taxonomic and functional composition of metagenomes from each depth zone, which was driven by differences in physical and chemical parameters. In parallel, a total of 40 metagenome-assembled genomes were obtained, which recovered one third of the total community. Phylogenomic reconstruction revealed that many of these genomes are derived from poorly characterized taxa of Bacteria and Archaea. Genomes derived from heterotrophic bacteria of the aphotic zone displayed a large apparatus of genes suited for the utilization of recalcitrant organic compounds such as cellulose, chitin and alkanes. In addition, we found genomic evidence suggesting that mixotrophic bacteria from the bathypelagic zone could perform carbon fixation through the Calvin-Benson-Bassham cycle, fueled by sulfur oxidation. Finally, we found that the viral communities shifted throughout the water column regarding their targeted hosts and virus-to-microbe ratio, in response to shifts in the composition and functioning their microbial counterparts. Our findings shed light on the microbial and viral drivers of important biogeochemical processes that take place in the South Atlantic Ocean.

Lean body mass: reference values for Italian population between 18 to 88 years old

OBJECTIVE

Body's lean mass compartment is a strong predictor of morbidity and mortality risk in various clinical conditions. This paper proposes a simple and easily applied reference table for lean body mass (LBM) and lean body mass index (LBMI) for the Italian population.

PATIENTS AND METHODS

Retrospective analysis of a database containing anthropometric and DXA body composition measurements obtained from a cross-sectional study conducted between 2002 and 2009 with Italian individuals. Parametric and nonparametric tests were performed using R 3.1.1 and SPSS 22.0 software packages.

RESULTS

The 3712 study participants, 37.3% men and 62.7% women, aging from 18 to 88 years. Individuals with normal weight, overweight and obesity were evenly distributed in the sample. LBM and LBMI measures were significantly higher in males. In both genders, there was a significant and progressive decline in these measures associated with aging. Significant differences in LBMI between genders were found in all age groups except for individuals over 75 years.

CONCLUSIONS

Based on the participants LBM profile, a reference table for LBM values was proposed. This reference will be useful to detect changes in the LBM compartment of individuals from the South Central Region of Italy, supporting health professionals during the process of diagnosing sarcopenia.

Feasibility of a combined strategy of HPV vaccination and screening in Mexico: the FASTER-Tlalpan study experience

There has been a noticeable shift in discussions about cervical cancer, moving from prevention to elimination. Interventions such as FASTER, human papillomavirus (HPV) vaccination and HPV screening are innovative intervention strategies which can be utilized to begin a path to elimination. To explore the feasibility of the FASTER strategy, an evaluation was carried out in eight primary health-care centers within the Tlalpan Health-Jurisdiction of Mexico City between March 2017 and August 2018. A mixed methods approach was used to evaluate three components: infrastructure, patient acceptability, and health-care professionals' perceptions. This included checklists of requirements for the infrastructure rollout of FASTER and interviews with women and health-care professionals. Nearly all (93%) of the 3,474 women aged 25-45 years accepted HPV vaccination as part of a combined vaccination and screening program. The main reason for acceptance was prevention, while having doubts about the vaccine's benefits was the main reason for refusal. Most of the 24 health-care professionals had a positive opinion toward HPV vaccination and identified the need to increase dissemination, inform the population clearly and concisely and currently extend the age range for vaccination. The evaluation of eight primary health-care centers showed they had the necessary infrastructure for the development of a joint HPV prevention strategy, but many centers required improvements to become more efficient. Together these findings suggest that although HPV vaccine acceptance was high, there is the need to increase education and awareness among potential vaccine recipients and health-care professionals to implement the FASTER strategy.

Des-Acyl Ghrelin Directly Targets the Arcuate Nucleus in a Ghrelin-Receptor Independent Manner and Impairs the Orexigenic Effect of Ghrelin

Ghrelin is a stomach-derived octanoylated peptide hormone that plays a variety of well-established biological roles acting via its specific receptor known as growth hormone secretagogue receptor (GHSR). In plasma, a des-octanoylated form of ghrelin, named des-acyl ghrelin (DAG), also exists. DAG is suggested to be a signalling molecule that has specific targets, including the brain, and regulates some physiological functions. However, no specific receptor for DAG has been reported until now, and, consequently, the potential role of DAG as a hormone has remained a matter of debate. In the present study, we show that DAG specifically binds to and acts on a subset of arcuate nucleus (ARC) cells in a GHSR-independent manner. ARC cells labelled by a DAG fluorescent tracer include the neuropeptide Y (NPY) and non-NPY neurones. Given the well-established role of the ARC in appetite regulation, we tested the effect of centrally administered DAG on food intake. We found that DAG failed to affect dark phase feeding, as well as food intake, after a starvation period; however, it impaired the orexigenic actions of peripherally administered ghrelin. Thus, we conclude that DAG directly targets ARC neurones and antagonises the orexigenic effects of peripherally administered ghrelin.

Analysis of brain nuclei accessible to ghrelin present in the cerebrospinal fluid

Ghrelin is a stomach-derived peptide hormone that acts in the brain to regulate many important physiological functions. Ghrelin receptor, named the growth hormone secretagogue receptor (GHSR), is present in many brain areas with or without obvious direct access to ghrelin circulating in the bloodstream. Ghrelin is also present in the cerebrospinal fluid (CSF) but the brain targets of CSF ghrelin are unclear. Here, we studied which brain areas are accessible to ghrelin present in the CSF. For this purpose, we centrally injected mice with fluorescein-labeled ghrelin (F-ghrelin) peptide tracer and then systematically mapped the distribution of F-ghrelin signal through the brain. Our results indicated that centrally injected F-ghrelin labels neurons in most of the brain areas where GHSR is present. Also, we detected F-ghrelin uptake in the ependymal cells of both wild-type and GHSR-null mice. We conclude that CSF ghrelin is able to reach most of brain areas expressing GHSR. Also, we propose that the accessibility of CSF ghrelin to the brain parenchyma occurs through the ependymal cells in a GHSR-independent manner.

Human papillomavirus prevalence, cervical abnormalities and risk factors among female sex workers in Lima, Peru

Female sex workers (FSWs) are at high risk of human papillomavirus (HPV) infection. Questionnaires were administered to 200 FSWs aged 18-26 years in Lima, Peru, to gather risk behaviours, and cervical swab samples were collected for Pap smears and HPV DNA testing as part of a longitudinal study. Participants reported a median of 120 clients in the past month, and 99.2% reported using condoms with clients. The prevalence of any HPV in cervical samples was 66.8%; 34 (17.1%) participants had prevalent HPV 16 or 18, and 92 (46.2%) had one or more oncogenic types. Fifteen women had abnormal Pap smears, 13 of which were HPV DNA positive. Fewer years since first sex was associated with oncogenic HPV prevalence in a model adjusted for previous sexually transmitted infection (STI) status and condom use with partners (prevalence ratio = 0.77, 95% confidence interval [CI] = 0.60-0.97). Our data confirm the high rates of HPV transmission among FSWs in Peru, highlighting the need for early and effective strategies to prevent cervical cancer.

Oral sex practices, oral human papillomavirus and correlations between oral and cervical human papillomavirus prevalence among female sex workers in Lima, Peru

Few data exist on oral human papillomavirus (HPV) prevalence in female sex workers (FSWs). Information regarding oral sex practices of 185 Peruvian FSWs, 18-26 years of age, was obtained via survey and compared with HPV testing results of oral rinse samples. Oral HPV prevalence was 14/185 (7.6%); four (28.9%) HPV genotypes were carcinogenic. One hundred and eighty-two participants reported having had oral sex; 95% reported condom use during oral sex with clients and 9.5% with partners. Women who had oral sex more than three times with their partners in the past month were more likely to have oral HPV than women who had oral sex three times or less (P = 0.06). Ten (71.4%) women with oral HPV were HPV-positive at the cervix; conversely 8.3% of women with cervical HPV were HPV-positive in the oral cavity. The prevalence of oral HPV was relatively low, considering the high rates of oral sex practiced by these women.

Withdrawal from methylphenidate increases neural reactivity of dorsal midbrain

Ritalin (methylphenidate hydrochloride, MP) is a non-amphetamine psychostimulant and is the drug of choice to treat children and adults diagnosed with the attention deficit hyperactivity disorder (ADHD). Several studies have demonstrated that rats treated with MP during early developmental stage exhibit alterations in anxiety-related processes such as an increased response to stressful stimuli and elevated plasma levels of corticosterone. Accordingly, the present study was designed to further characterize the neural and behavioral consequences of withdrawal from MP in adult rats and its influence on the neural reactivity of the dorsal midbrain. After initial exposure to an elevated plus-maze (EPM), brainstem neural activation, elicited by exposure to EPM aversive cues, was analyzed using a Fos-protein immunolabeling technique. Additional independent groups of animals were submitted to electrical stimulation of the dorsal column (DPAG) or the startle response procedure, in order to verify the influence of withdrawal from MP on the expression of unconditioned fear induced by DPAG activation and the effects of or withdrawal from MP on motor response, respectively. Our results provide new findings about the influence of MP treatment in adult rats, showing that, after a sudden MP treatment-break, increased anxiety, associated with the neural sensitization of anxiety-related regions, ensues.

Effect of rutin and chloroquine on White Leghorn chickens infected with Plasmodium (Bennettinia) juxtanucleare

Plasmodium juxtanucleare is one of the agents that cause avian malaria in chickens and little is known about the treatment of the infection. The aim of this study was to compare the antimalarial activities of rutin and chloroquine in chickens infected with P. juxtanucleare after immunosuppression with corticosteroid. Antimalarial activity was verified in 33 fowls by evaluation of parasitemia levels in Giemsa-stained blood smears taken to 30 days. Rutin did not exert a reduction in parasitemia from P. juxtanucleare when compared to chloroquine treatment that kept the parasites at a low level, demonstrating its antimalarial effect. During the course of the infection, the trophozoite stage predominated (80%), followed by schizont (17%) and gametocyte (3%). Maximum parasitemia levels were recorded on day 12 in control and rutin groups. There were no significant differences in the hematocrit values, weight body or the temperature of the fowls among the groups evaluated (p > 0.05).

Stereotypies in Rett syndrome: Analysis of 83 patients with and without detected MECP2 mutations

BACKGROUND

Hand stereotypies are considered a hallmark of Rett syndrome (RTT) and are usually described as symmetric movements at the midline. However, related pathologies may show the same type of involuntary movement. Furthermore, patients with RTT also have stereotypies with other localizations that are less well characterized.

METHODS

We analyzed stereotypies in 83 patients with RTT, 53 with and 30 without a mutation detected in the MECP2 gene. Patients were observed and videotaped always by the same pediatric neurologist. Stereotypies were classified, and data were submitted to statistical analysis for comparison of mutation-positive and -negative patients and analysis of their evolution with the disease.

RESULTS

All the patients showed hand stereotypies that coincided with or preceded the loss of purposeful hand movements in 62% of the patients with MECP2 mutations. The hair pulling stereotypy was more frequent in the group with detected mutations, whereas hand washing was not. Hand gaze was absent in all RTT patients with MECP2 mutations. Patients with MECP2 mutations also had more varied stereotypies, and the number of stereotypies displayed by each patient decreased significantly with age in this group. In all patients, stereotypies other than manual tended to disappear with the evolution of the disease.

CONCLUSIONS

Although symmetric midline hand stereotypies were not specific to patients with an MECP2 mutation, some of the other stereotypies seemed to be more characteristic of this group. In patients younger than 10 years and meeting the necessary diagnostic criteria of Rett syndrome, the association of hand stereotypies without hand gaze, bruxism, and two or more of the other stereotypies seemed to be highly indicative of the presence of an MECP2 mutation.

Unequivocal morphological diagnosis of fungi in morphologically abnormal nails

AIMS

To analyse the prevalence of fungi in abnormal nails by morphological diagnosis. Prevalence studies of onychomycoses in temperate climate zones have yielded widely varying rates, possibly reflecting the confounding effects of referral bias, sampling specificity and intrinsic sensitivity of the diagnostic techniques employed.

METHODS AND RESULTS

The method employed to identify fungi in nails entailed primary fixation using a non-formaldehyde-based coagulative fixative (BoonFix; Finetec, Japan) and microwave-enhanced processing to histology, followed by staining the paraffin sections with periodic acid-Schiff, using haematoxylin as a routine counterstain. The results of 990 nail samples were tabled for statistical analysis related to gender, patient age and diabetes mellitus status. In four of the 990 (< 1%) analysed cases the diagnosis was found to be equivocal using the method employed. These cases were jointly reviewed for definitive diagnosis. The overall prevalence of invasive hyphal structures was found to be 606/990 (approximately 61%). The relative risk for fungal infection in morphologically abnormal nails was found to be higher for persons < 20 years old or diabetic patients aged > or = 71 years.

CONCLUSIONS

The 61% positivity rate for fungi found justifies systematic direct submission of samples from abnormal nails for histological confirmation in order to avoid unwarranted treatment.

Fear state induced by ethanol withdrawal may be due to the sensitization of the neural substrates of aversion in the dPAG

The neural substrate underlying the aversive effects induced by ethanol abstinence is still unclear. One candidate for such effects is the dorsal periaqueductal gray (dPAG), a core structure of the brain aversion system. The main aim of this study is to examine the role of the dPAG as a possible locus of the aversive effects following abrupt alcohol withdrawal. To this end, rats were subjected to an oral ethanol self-administration procedure, in which animals were offered 6-8% (v/v) ethanol solution for a period of 21 days followed by an abrupt discontinuation of the treatment on the two subsequent days. Control animals received control dietary fluid for similar periods of time. The effects of ethanol withdrawal were examined in the elevated plus-maze (EPM) (Exp. I), on the prepulse inhibition of startle to loud sounds (Exp. II) and on the freezing and escape responses induced by electrical stimulation of the dPAG (Exp. III). In Experiment III, rats were implanted with an electrode aimed at the dPAG and the number and duration of ultrasonic vocalizations (USVs) were also recorded in the rats that received dPAG stimulation at freezing and escape thresholds. Data obtained showed that ethanol withdrawal elicited significant "anxiety-like" behaviors, as revealed by the decrease in the number of entries into and time spent onto the open arms of the EPM. Startle reflex and prepulse inhibition remained unchanged in withdrawn animals. In addition, discontinuation from the chronic ethanol regimen caused a reduction in the stimulation thresholds for freezing and escape and in the number and duration of USVs. Together, these effects have been interpreted in the frame of a high fear state elicited by activation of the dPAG. These findings are indicative that ethanol withdrawal sensitizes the substrates of fear at the level of this midbrain structure.

Molecular studies in Portuguese patients with Smith-Lemli-Opitz syndrome and report of three new mutations in DHCR7

Smith-Lemli-Opitz syndrome (SLO) is an autosomal recessive disorder characterised by craniofacial dysmorphism, mental retardation, multiple congenital anomalies, and increased levels of 7-dehydrocholesterol (7-DHC) in body tissues and fluids. SLO is caused by mutations in the DHCR7 gene which encodes 7-dehydrocholesterol reductase, the last enzyme of cholesterol biosynthesis pathway. In our investigation, we screened 682 dysmorphic/mentally retarded Portuguese patients for abnormal levels of 7-DHC in blood by UV spectrometry. We identified six unrelated patients with SLO (0.87% of total). Mutational analysis of the DHCR7 gene led to the identification of seven distinct mutations, three of which are new (F174S, H301R, and Q98X). The common IVS8-1G > C and T93M variants together with the H301R accounted for 70% of the all SLO alleles in our population. Our findings contribute to the variegate array of pathological changes in the DHCR7 gene among different European populations.

SPRR4, a novel cornified envelope precursor: UV-dependent epidermal expression and selective incorporation into fragile envelopes

The cornified cell envelope (CE), a structure formed in the outermost layers of stratified squamous epithelia, provides a physical barrier against environmental insults. It is composed of several structural proteins, which are irreversibly crosslinked by calcium-activated transglutaminases. The small proline rich proteins (SPRRs) are one set of CE precursors. SPRR4, a novel member of this gene family, displayed very low or undetectable expression levels in normal human skin or other stratified squamous epithelia, but was clearly induced by UV light both in vivo and in vitro. High epidermal expression of SPRR4 was monitored only after chronic UV exposure and was concomitant with a thickening of the stratum corneum, which is believed to provide protection against subsequent damage. The calcium-dependent translocation of an SPRR4-GFP fusion protein to the cell periphery in living keratinocytes and its integration into both rigid and fragile cornified envelopes proved that SPRR4 is a novel CE precursor. Interestingly, after UV irradiation, SPRR4 was selectively incorporated into fragile CEs. Our results show for the first time that UV-induced cornification is accompanied by qualitative changes in CE precursor assembly. SPRR4 is part of an adaptive tissue response to environmental stress, which is likely to compensate for UV induced impairment of the epidermal barrier function.

Intraoperative sentinel lymph node mapping in patients with colon cancer

BACKGROUND

The sentinel lymph node (SLN) mapping technique has been used in breast cancer and melanoma, and was recently described for colon cancer.

METHODS

Thirty-five patients with colon cancer underwent intraoperative SLN mapping. One milliliter of 1% isosulfan blue was injected subserosally around the tumor. The first nodal area that was highlighted with blue was identified as the SLN. All lymph nodes underwent examination with hematoxylin and eosin (H&E) stain. SLNs underwent additional sectioning and were stained with CAM 5.2.

RESULTS

Lymphatic mapping adequately identified the SLN in 25 patients (71%). In the 15 cases where the SLNs were negative for metastases, all other non-SLNs were also negative (0% false negative rate). The SLN was the only site of metastases in 6 (17%) of 35 patients. CAM 5.2 staining provided the only evidence of micrometastases in 4 (11%) of 35 patients.

CONCLUSIONS

Intraoperative SLN mapping is a feasible technique with a reasonable SLN identification rate (71%). The absence of metastases in the SLNs accurately predicts the status of the non-SLNs. Tumors in 11% of patients were upstaged by the demonstration of micrometastatic involvement, and these patients may benefit from further adjuvant chemotherapy.

Structural organization and regulation of the small proline-rich family of cornified envelope precursors suggest a role in adaptive barrier function

The protective barrier provided by stratified squamous epithelia relies on the cornified cell envelope (CE), a structure synthesized at late stages of keratinocyte differentiation. It is composed of structural proteins, including involucrin, loricrin, and the small proline-rich (SPRR) proteins, all encoded by genes localized at human chromosome 1q21. The genetic characterization of the SPRR locus reveals that the various members of this multigene family can be classified into two distinct groups with separate evolutionary histories. Whereas group 1 genes have diverged in protein structure and are composed of three different classes (SPRR1 (2x), SPRR3, and SPRR4), an active process of gene conversion has counteracted diversification of the protein sequences of group 2 genes (SPRR2 class, seven genes). Contrasting with this homogenization process, all individual members of the SPRR gene family show specific in vivo and in vitro expression patterns and react selectively to UV irradiation. Apparently, creation of regulatory rather than structural diversity has been the driving force behind the evolution of the SPRR gene family. Differential regulation of highly homologous genes underlines the importance of SPRR protein dosage in providing optimal barrier function to different epithelia, while allowing adaptation to diverse external insults.

Mutation analysis of the GCDH gene in Italian and Portuguese patients with glutaric aciduria type I

Two novel (G390V and X439W) and five already known mutations were identified in a total of 14 GA I alleles from Italy and Portugal. The substitution X439W is a rare type of mutation, which breaks the stop codon of the GCDH gene. As described in other populations, R402W was the most common mutation. Genotype R227P/R402W was found in a patient with low glutarate excretion. Haplotype studies have also been performed.

The correlation of genotype and phenotype in Portuguese hyperphenylalaninemic patients

To understand the basis for the clinical heterogeneity of phenylalanine hydroxylase deficiency among Portuguese hyperphenylalaninemic patients, genotype-phenotype correlations were established. A group of 61 patients was completely genotyped, leading to the identification of 20 different mutant alleles in 36 different genotypic combinations, including a mutant allele not reported previously. The severity of those mutations found within this hyperphenylalaninemic population, which have not been previously expressed in vitro, were assessed. The results obtained by the present study exhibit a strong correlation between the predicted residual enzyme activity, as deduced from the genotype of the patients, and the biochemical phenotype represented by the diagnostic parameters (phenylalanine levels before the beginning of treatment and the dietary phenylalanine tolerance). It was observed that only a judicious follow-up and compliance with the appropriate diet permits the correct assessment of the clinical phenotype of the patients. Additionally, based upon the correlation observed between genotypes and diagnostic parameters, it was possible to predict the potential residual enzyme activity of those mutations (identified in our patients) which have not yet been studied in vitro.

Human epidermal differentiation complex in a single 2.5 Mbp long continuum of overlapping DNA cloned in bacteria integrating physical and transcript maps

Terminal differentiation of keratinocytes involves the sequential expression of several major proteins which can be identified in distinct cellular layers within the mammalian epidermis and are characteristic for the maturation state of the keratinocyte. Many of the corresponding genes are clustered in one specific human chromosomal region 1q21. It is rare in the genome to find in such close proximity the genes belonging to at least three structurally different families, yet sharing spatial and temporal expression specificity, as well as interdependent functional features. This DNA segment, termed the epidermal differentiation complex, contains 27 genes, 14 of which are specifically expressed during calcium-dependent terminal differentiation of keratinocytes (the majority being structural protein precursors of the cornified envelope) and the other 13 belong to the S100 family of calcium binding proteins with possible signal transduction roles in the differentiation of epidermis and other tissues. In order to provide a bacterial clone resource that will enable further studies of genomic structure, transcriptional regulation, function and evolution of the epidermal differentiation complex, as well as the identification of novel genes, we have constructed a single 2.45 Mbp long continuum of genomic DNA cloned as 45 p1 artificial chromosomes, three bacterial artificial chromosomes, and 34 cosmid clones. The map encompasses all of the 27 genes so far assigned to the epidermal differentiation complex, and integrates the physical localization of these genes at a high resolution on a complete NotI and SalI, and a partial EcoRI restriction map. This map will be the starting resource for the large-scale genomic sequencing of this region by The Sanger Center, Hinxton, U.K.

Hepato-splanchnic blood flow and oxygen extraction capabilities during experimental tamponade: effects of endotoxin

We studied the hepato-splanchnic vascular response and changes in O2 extraction capabilities to a reduction in blood flow following endotoxemia. Fourteen anesthetized and mechanically ventilated dogs were divided into two groups of seven each. Group 1 received 2 mg/kg of E. coli endotoxin, and group 2 served as a control. After initial fluid resuscitation following endotoxic shock, regional blood flow estimated by an ultrasonic technique increased similarly in the hepatic artery, portal vein, and mesenteric artery, but microvascular blood flow estimated by a laser Doppler technique was lower in the liver than in the intestinal mucosa. When blood flow was reduced by cardiac tamponade, endotoxin-treated animals had greater whole body and regional critical O2 delivery (DO2crit) and lower whole body, liver, and intestinal critical O2 extraction ratios (O2ERcrit). DO2crit was higher in the liver than in intestine but O2ERcrit was similar in the two organs. Whole body DO2crit at the onset of organ O2 supply dependency was similar under control (9.4 +/- 1.9 mL/kg. min for whole body, 10.3 +/- 4.7 mL/kg. min for liver, and 10.0 +/- 2.6 mL/kg. min for intestine) and endotoxic conditions (13.6 +/- 3.2 mL/kg. min for whole body, 15.6 +/- 2.7 mL/kg. min for liver, and 15.4 +/- 8.7 mL/kg. min for intestine). We conclude that fluid-resuscitated endotoxic shock in dogs is characterized by blood flow redistribution within the liver and intestine. Microvascular depression may be more severe in the liver than in the intestinal mucosa, although the whole body, the liver, and the intestine became O2 supply-dependent simultaneously.

[Branched chain amino acid diseases]

The authors present 19 cases of branched-chain AA catabolism disease: 9 Maple Syrup Urine Diseases, 6 Methylmalonic Acidemias, 2 Propionic Acidemias, 1 case of 3-OH-3-methylglutaryl-CoA-lyase deficiency and another of 2-methyl-ketoacetyl-CoA-thiolase deficiency. Fifteen are early neonatal forms and in 4 the onset occurred later. Fifteen patients (78.9%) needed one or several extra-corporal procedures either in the initial acute phase or during relapse. Fifteen patients presented several metabolic relapses, sometimes fatal (3 children). Global mortality was 26.3%, that is 5/19 patients: 4 children with neonatal forms, one with a later onset. Eleven patients (57.9%) had an IQ/DQ > or = 80: only 46.6% of the neonatal forms obtained these results, in contrast with all the late onset forms. Of the survivors, 9 (64.2%), presented a residual neurologic condition. The correct diagnostic and treatment procedures are defined and the need to consider the existence of these diseases at any age, particularly in the neonatal period, is stressed.

Effects of nitric oxide on blood flow distribution and O2 extraction capabilities during endotoxic shock

The effects of the nitric oxide (NO) synthase inhibitor NG-monomethyl-L-arginine (L-NMMA) and the NO donor 3-morpholinosydnonimine (SIN-1) were tested in 18 endotoxic dogs. L-NMMA infusion (10 mg . kg-1 . h-1) increased arterial and pulmonary artery pressures and systemic and pulmonary vascular resistances but decreased cardiac index, left ventricular stroke work index, and blood flow to the hepatic, portal, mesenteric, and renal beds. SIN-1 infusion (2 microg . kg-1 . min-1) increased cardiac index; left ventricular stroke work index; and hepatic, portal, and mesenteric blood flow. It did not significantly influence arterial and pulmonary artery pressures but decreased renal blood flow. The critical O2 delivery was similar in the L-NMMA group and in the control group (13.3 +/- 1.6 vs. 12.8 +/- 3.3 ml . kg-1 . min-1) but lower in the SIN-1 group (9.1 +/- 1.8 ml . kg-1 . min-1, both P < 0.05). The critical O2 extraction ratio was also higher in the SIN-1 group than in the other groups (58.7 +/- 10.6 vs. 42.2 +/- 7.6% in controls, P < 0.05; 43.0 +/- 15.5% in L-NMMA group, P = not significant). We conclude that NO is not implicated in the alterations in O2 extraction capabilities observed early after endotoxin administration.

Treatment with a platelet-activating factor antagonist has little protective effects during endotoxic shock in the dog

Platelet-activating factor (PAF) is a potent vasoactive and inflammatory lipid mediator which has been implicated in the hemodynamic alterations of endotoxemia and sepsis. Different PAF receptor antagonists have been shown to attenuate the systemic and pulmonary disturbances of sepsis, but they were generally administered before the injection of endotoxin and their effects have not been consistent. To examine the effects of BB-882, a novel potent PAF receptor antagonist, on general hemodynamics and regional flow distribution in a canine endotoxic shock model, 14 anesthetized and ventilated dogs received 2 mg/kg of Escherichia coli endotoxin intravenously (i.v.) followed by generous fluid resuscitation. Thirty minutes later, the dogs received either BB-882 (n = 7) as a continuous i.v. infusion with hourly increasing doses (2, 5, and 10 mg/kg.h, respectively) or a corresponding amount of saline (n = 7). The administration of BB-882 resulted in a dose-dependent reduction in cardiac output and an increase in systemic and pulmonary vascular resistance. Mesenteric and renal flow were not different from control values whereas femoral blood flow progressively decreased. Another group of 7 dogs received 5 mg/kg i.v. bolus of BB-882 30 min before endotoxin. Pretreatment significantly increased mesenteric blood flow by about 50% but did not show any significant hemodynamic effects. This study demonstrates that the administration of a PAF receptor antagonist following endotoxic shock in fluid resuscitated dogs does not offer significant hemodynamic benefit. Pretreatment with BB-882 at the dose used only enhanced mesenteric perfusion. These findings do not support beneficial effects of PAF receptor antagonists in septic shock.

Effects of norepinephrine on regional blood flow and oxygen extraction capabilities during endotoxic shock

We explored the effects of norepinephrine on blood flow distribution and oxygen extraction capabilities during hyperdynamic endotoxic shock. Twelve anesthetized and mechanically ventilated dogs received 2 mg/kg of Escherichia coli endotoxin followed by a general saline infusion and were then randomly divided into two groups: six received norepinephrine (1 microg/kg/min), and six served as control subjects. The norepinephrine group maintained higher mean arterial pressure, cardiac index, left ventricular stroke work index, and hepatic arterial blood flow without altering blood flow to portal, mesenteric, and renal beds. When cardiac tamponade was induced to study tissue oxygen extraction capabilities, the norepinephrine group had a lower critical oxygen delivery in whole body (11.5 +/- 5.2 versus 14.3 +/- 1.4 ml/kg/min, p < 0.05) and in liver (25.0 +/- 11.3 versus 38.0 +/- 9.0 ml/min, p = NS) and a higher critical oxygen extraction ratio in whole body (53.8 +/- 17.7 versus 32.0 +/- 6.1%, p < 0.05), and in liver (57.0 +/- 11.9 versus 35.2 +/- 4.3%, p < 0.05). We conclude that during endotoxic shock in dogs, norepinephrine hardly influences blood flow distribution and could even increase hepatic artery blood flow, and it can also improve whole body and liver oxygen extraction capabilities.

[Restrictive myocardiopathy in children]

Four children, three males and one female, aged 1.5 months to 11 years, with restrictive cardiomyopathy are described. One had patent ductus arteriosus in association. Hepatomegaly, abnormal second heart sound and signs of pulmonary venous congestion in chest X-ray were the most consistent clinical findings. Diagnosis was based on echocardiographic findings, cardiac catheterization data and results of pathology. The most frequent echocardiographic sign was the enlargement of both atria but with the ventricles within normal size and normal systolic function. Abnormalities in second phase of the ventricular filling were recorded in 2D-echo Doppler and cardiac catheterization, where a dip and plateau morphology of ventricular tracings was recorded. Metabolic studies performed in two children were normal, and any child had hypereosinophilia. Two children died, one was lost for follow-up and another is asymptomatic. Remarks on medical and surgical management are made.

[The acquired immunodeficiency syndrome, hypertrophic myocardiopathy and multivalvular infectious endocarditis. Apropos a clinical case]

We present a clinical case of a 33 years old young male, gypsy, intravenous drug abuser with heroine and cocaine and AIDS diagnosis. The clinical anamnesis was mainly fever and systolic heart murmur in a clinical scenario of AIDS. The two-dimensional echocardiographic study was clearly diagnostic of an hypertrophic obstructive cardiomyopathy of the left ventricle. This study showed also the presence of multiple vegetations of the mitral, aortic and pulmonic valves in a clinical setting of an acute Streptococcus Viridans infective endocarditis. In this case report we discuss the incidence of this type of multiple cardiac lesions and particularly the presence of this specific pathogenic agent in this high risk group of patients with intravenous drug abuse and systemic immunosuppression. We pointed out the rarity of these findings of left side valvular vegetations associated with this type of cardiomyopathy and the different factors related to infective endocarditis.

[Pulmonary hypertension in generalized lupus erythematosus]

Two young women with systemic lupus erythematosus and pulmonary hypertension are reported. Both patients had Raynaud phenomenon and antibodies to cardiolipin. They seem to be potentially associated in the pathogenesis. Also, laboratory and hemodynamic findings were discussed. Although the treatment, the prognosis still bad.

[Ceroid-lipofuscinosis: ultrastructural study of 8 cases]

The authors studied the clinical and ultrastructural features of 8 cases of Neuronal Ceroid-Lipofuscinosis (NCL). Five cases of the late-infantile type and 3 cases of the juvenile type. The clinical diagnosis of all cases was confirmed by the electron microscopy analysis of the peripheral blood lymphocytes and biopsy material from the skin, palpebral conjunctiva, skeletal muscle and rectal mucosa. Our observations agree with previous reports concerning the predominance of curvilinear bodies in the cells of the late infantile type, and fingerprint-like structures in those of the juvenile type. The finding of parallel tubular arrays and NCL inclusions associated in the same lymphocyte (frequently in the same vacuole) suggests that those structures could be related to the metabolic error of NCL. Ultrastructural examination of microbuffycoats of peripheric blood lymphocytes is a simple, time-saving and reliable method that allows specific confirmation of a clinical diagnosis of Neuronal Ceroid-Lipofuscinosis.