Building research capacity for sickle cell disease in Africa: Lessons and challenges from establishing a birth cohort in Tanzania

Sickle Cell Disease (SCD) is a known public health burden in sub-Saharan Africa (SSA). The manifestation of SCD starts in early childhood and if not well-managed may lead to early death (before the age of 5 years). Understanding the underlying mechanisms that influence early SCD manifestation is of great importance for early disease and intervention management which will in turn, reduce both morbidity and mortality rates in children. One approach of achieving this is by establishing SCD birth cohorts that can be followed for a period of time (3-5 years) whilst documenting necessary information related to early childhood illnesses. To date, there are few SCD birth cohorts in Africa. To address this gap, we have established a birth cohort of babies with and without SCD (with sickle cell trait and healthy babies). These babies are followed up for 3 years with their study visits synchronized to the immunization schedule. During enrollment and follow-up visits, information on demographic, clinical, and laboratory parameters are collected. To date, we have enrolled a total of 341 babies with and without SCD. Out of these, a total of 311, 186, 133, 81, 44, and 16 babies have returned for their 1st, 2nd, 3rd, 4th, 5th, and 6th visits, respectively. We have collected both demographic and clinical information for these babies at enrollment and during follow-up. We have also utilized this platform to learn on the best approaches of establishing and maintaining a research birth cohort in an African context. We have analyzed the practical issues pertaining to the integration of the birth cohort with the immunization platform which seems to be the most effective and sustainable strategy for maintaining a birth cohort in our context.

The Retornus-2 study: impact of respiratory muscle training in subacute stroke patients with dysphagia, study protocol of a double-blind randomized controlled trial

Background

Stroke can lead to varying degrees of oropharyngeal dysphagia, respiratory muscle dysfunction and even increase medical complications such as aspiration, malnutrition and death. Recent studies suggest that inspiratory and expiratory respiratory muscle training (IEMT) can improve swallowing efficacy and may reduce aspiration events. The main purpose of this study is to examine whether an 8-week IEMT programme can improve respiratory muscle strength and swallow dysfunction severity in subacute stroke patients with dysphagia.

Methods

Retornus-2 is a two-arm, prospectively registered, randomized controlled study with blinded assessors and the participation of fifty individuals who have suffered a stroke. The intervention group undergoes IEMT training consisting of 5 sets of 10 repetitions, three times a day for 8 weeks. Training loads increase weekly. The control group undergoes a sham-IEMT protocol. The primary outcome examines the efficacy of the IEMT protocol to increase respiratory muscle strength and reduce dysphagia severity. The secondary outcome assesses the longitudinal impact of dysphagia on body composition and nutritional assessment over a 6-month follow-up.

Discussion

IEMT induces an improvement in respiratory muscle strength and might be associated with relevant benefits in dysphagia patterns, as well as a reduction in the number of aspiration events confirmed by videofluoroscopy or fiberoptic endoscopic evaluation of swallowing. The description of the impact of swallowing impairment on nutritional status will help develop new strategies to face this known side-effect.

Trial registration

Clinicaltrials.gov NCT03021252. Registered on 10 January 2017. https://clinicaltrials.gov/ct2/results?cond=retornus+2&term=&cntry=ES&state=&city=&dist=

WHO trial Registration data set: Due to heavy traffic generated by the COVID-19 outbreak, the ICTRP Search Portal does not respond. The portal recommends other registries such as clinicaltrials.gov. Protocol version: RETORNUS 2_ PROTOCOL_2.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05353-y.

Engaging a wider public health workforce: bringing public health into architecture education

Background

Current public health challenges necessitate the closer working of public health with built environment professionals. Despite growing evidence of benefits, there remains little progress in practice. Architects can play a key role in ensuring urban and building design is health promoting, however there is no requirement to teach health by architectural accreditation bodies across Europe.

Objectives

In the United Kingdom in 2010, the Public Health Practitioner in Residence programme (PHPiR) was established to address this situation. Public health professionals are embedded within the Faculty of Environment and Technology at the University of the West of England, and contribute to research, pedagogic programme development, teaching and mentoring. The aim was to embed public health concepts and issues into architecture training, to empower the profession as part of the wider workforce, to improve health and wellbeing when designing buildings and places. The PHPiR was evaluated using the Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework. Data was collected (questionnaires, focus group, semi-structured interviews, programme documentation) on a Masters of Architecture cohort (N = 34) at intervals from 2011-2019 to see if the PHPiR has long lasting effects as students enter practice.

Results

Public health concepts including; inequalities, life course approach, and social capital, became embedded into the architecture curriculum. Projects produced had increased reference to wider health promoting issues and participants thinking shifted from the building itself to who would use the building, suggesting the intervention achieved its aims.

Conclusions

The PHPiR offers a novel approach for built environment professions to better understand public health issues and the relevance to their chosen fields. This model could be applied to other courses and replicated in educational institutions and public health training programmes across Europe.

Key messages

The PHPiR influenced the architecture curriculum, improved architects understanding and public health issues and concepts, and empowered them to create more health promoting environments. Embedding public health professionals into training for other disciplines may be an effective, sustainable method for increasing the wider public health workforce.

Translation and Validation of the Spanish Version of the SARC-F Questionnaire to Assess Sarcopenia in Older People

OBJECTIVES

The revised European consensus on sarcopenia definition and diagnosis (EWGSOP2) includes the SARC-F questionnaire, the most valid and consistent sarcopenia screening tool, as the mandatory first step. Our aim was the translation, cross-cultural adaptation, and validation of the SARC-F questionnaire as a culturally-responsive Spanish-language version for the European population.

STUDY DESIGN

Cross-sectional descriptive study, applying the two-step WHO methodology for translation and cross-cultural adaptation of health questionnaires, and harmonization with the Mexican-Spanish version. European Union Geriatric Medicine Society recommendations for SARC-F validation in European languages were considered.

PARTICIPANTS

Outpatient clinics of a university hospital.

INCLUSION CRITERIA

stable, ambulatory (including aids), community-dwelling population ≥65 years old.

MAIN OUTCOME MEASURES

The self-reported 5-item SARC-F questionnaire was administered; scores ≥4 indicated sarcopenia. Sensitivity, specificity, accuracy-likelihood ratios, predictive values, and kappa statistics were calculated and consecutively compared with European Working Group on Sarcopenia in Older People (EWGSOP) and EWGSOP2 criteria.

RESULTS

This Spanish version, administered in an average 70s, has adequate internal consistency (Cronbach alpha=0.779). For the validation study, 90 (43.3%) of 208 potentially eligible subjects (81.4 ± 5.9 years old, 75.6% women) were included. SARC-F identified 51 (56.7%) subjects with sarcopenia and 39 (43.3%) without the disease. Prevalence was 17.8% per EWGSOP and 25.6% per EWGSOP2 (58% accuracy and fair agreement: sensitivity, 78.3%; specificity, 50.8%).

CONCLUSIONS

SARC-F is a feasible tool, suitable for bedside assessment in community-dwelling older patients. Wide diffusion of this culturally-responsible SARC-F Spanish version is expected as EWGSOP2 is adopted and sarcopenia assessment is broadly implemented in Spain.

Secondary organic aerosol origin in an urban environment: influence of biogenic and fuel combustion precursors

Source contributions of organic aerosol (OA) are still not fully understood, especially in terms of quantitative distinction between secondary OA formed from anthropogenic precursors vs. that formed from natural precursors. In order to investigate the OA origin, a field campaign was carried out in Barcelona in summer 2013, including two periods characterized by low and high traffic conditions. Volatile organic compound (VOC) concentrations were higher during the second period, especially aromatic hydrocarbons related to traffic emissions, which showed a marked daily cycle peaking during traffic rush hours, similarly to black carbon (BC) concentrations. Biogenic VOC (BVOC) concentrations showed only minor changes from the low to the high traffic period, and their intra-day variability was related to temperature and solar radiation cycles, although a decrease was observed for monoterpenes during the day. The organic carbon (OC) concentrations increased from the first to the second period, and the fraction of non-fossil OC as determined by ¹⁴C analysis increased from 43% to 54% of the total OC. The combination of ¹⁴C analysis and Aerosol Chemical Speciation Monitor (ACSM) OA source apportionment showed that the fossil OC was mainly secondary (>70%) except for the last sample, when the fossil secondary OC only represented 51% of the total fossil OC. The fraction of non-fossil secondary OC increased from 37% of total secondary OC for the first sample to 60% for the last sample. This enhanced formation of non-fossil secondary OA (SOA) could be attributed to the reaction of BVOC precursors with NO_x emitted from road traffic (or from its nocturnal derivative nitrate that enhances night-time semi-volatile oxygenated OA (SV-OOA)), since NO₂ concentrations increased from 19 to 42 μg m⁻³ from the first to the last sample.

Evidence that periweaning failure-to-thrive syndrome (PFTS) has a genetic predisposition

Genetic susceptibility or resistance to diseases is currently drawing increasing attention. This work describes two different breeding herds showing signs of periweaning failure-to-thrive syndrome (PFTS), an emergent swine disease. The disease was diagnosed based on clinical picture and confirmed by histopathology. The possibility of main infectious pathogens was ruled out by immunohistochemistry and PCR. In a simple approach, sires of the affected piglets have been determined using microsatellite paternity analysis, including a healthy group in each case. In each of the two farms, a single boar was found to have sired 45-50 per cent sick animals. Removal of this sire from two farms resulted in a significant decrease in the prevalence of the disease among the offspring, in accordance with other two cases diagnosed, although without including a control group. Since the analysed animals belonged to three different genetic lines, these findings point to the existence of individual genetic susceptibility to this syndrome.

Phenotypic clustering of yeast mutants based on kinetochore microtubule dynamics

MOTIVATION

Kinetochores are multiprotein complexes which mediate chromosome attachment to microtubules (MTs) of the mitotic spindle. They regulate MT dynamics during chromosome segregation. Our goal is to identify groups of kinetochore proteins with similar effects on MT dynamics, revealing pathways through which kinetochore proteins transform chemical and mechanical input signals into cues of MT regulation.

RESULTS

We have developed a hierarchical, agglomerative clustering algorithm that groups Saccharomyces cerevisiae strains based on MT-mediated chromosome dynamics measured by high-resolution live cell microscopy. Clustering is based on parameters of autoregressive moving average (ARMA) models of the probed dynamics. We have found that the regulation of wildtype MT dynamics varies with cell cycle and temperature, but not with the chromosome an MT is attached to. By clustering the dynamics of mutants, we discovered that the three genes IPL1, DAM1 and KIP3 co-regulate MT dynamics. Our study establishes the clustering of chromosome and MT dynamics by ARMA descriptors as a sensitive framework for the systematic identification of kinetochore protein subcomplexes and pathways for the regulation of MT dynamics.

AVAILABILITY

The clustering code, written in Matlab, can be downloaded from http://lccb.scripps.edu. ('download' hyperlink at bottom of website).

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

[Short form 36 health questionnaire in hemiplegic patients 2 years after stroke]

INTRODUCTION

Many studies show that subjects with sequelae after stroke have a worse health perception in western societies. Due to the shortage of papers on the Spanish population in this regard, a study was carried out to assess health perception in hemiplegic patients 2 years after stroke in comparison with that of the general population and correlate health perception with demographic, clinical and functional variables.

METHODS

Cross-sectional study of 212 community stroke survivors. The main variables collected were: health perception assessed with the Short Form 36 (SF-36), disability assessed with the motor Functional Independence Measure (FIM) and Geriatric Depression Scale (GDS). Statistical tests used: chi2, Student t test and Spearman correlation coefficient.

RESULTS

In comparison with the Spanish general population, health perception in hemiplegic male stroke patients is diminished in all areas. In hemiplegic female patients, physical function is the only subscale significantly affected in all age groups. Variables related to worse health perception are: presence of depression, dependence and the belief of the need for kind of social support, A significant correlation was observed between SF-36 values and the motor FIM (r = 0.737 with physical function) and the GDS (r = -0.821 with mental health).

CONCLUSIONS

Health perception in hemiplegic patients 2 years after stroke is diminished in comparison with that 348 of the general population. Factors which determine worst health perception are depression, motor dependence, need of caregiver assistance and need of social support.

Do different mechanisms underlie two anxiogenic effects of systemic nicotine?

Alpha7 nicotinic acetylcholine receptors (alpha7 nAChRs) and 5-hydroxytryptamine 1A (5-HT1A) receptors have been implicated in the anxiogenic effects of centrally administered nicotine, but the receptors that mediate the anxiogenic effects of systemic nicotine are not known. This study explored whether competitive nAChR antagonists [dihydro-beta-erythroidine (DHbetaE), 4 mg/kg, and methyllycaconitine (MLA), 5 mg/kg], and a 5-HT1A receptor antagonist (WAY 100635, 0.5 and 1 mg/kg) could block the effects of two anxiogenic doses of nicotine in the social interaction test of anxiety. The anxiogenic effect of 0.1 mg/kg nicotine, given 5 min before the test, was blocked by DHbetaE and WAY 100635, establishing roles for alpha4beta2 nAChRs and 5-HT1A receptors. None of the antagonists could block the effect of 0.45 mg/kg nicotine, given 30 min before the test, precluding firm conclusions about the mechanisms underlying this anxiogenic effect. However, there was evidence for a role of alpha7 nAChRs in mediating an endogenous anxiogenic tone, since MLA itself had an anxiolytic effect that was blocked by both doses of nicotine. Thus, both alpha7 and alpha4beta2 nAChRs might have a role in mediating the anxiogenic effects of nicotine.

Organochlorine compounds and concentrations of thyroid stimulating hormone in newborns

AIMS

To assess the association between prenatal exposure to organochlorine compounds and thyroid status in newborns from an area with high levels of hexachlorobenzene (HCB).

METHODS

A total of 98 mother-infant pairs (83.1% of all children born during the period 1997-99 in a specific area polluted with HCB) were recruited. Levels of organochlorine compounds were measured in 70 cord serum samples. Concentrations of thyroid stimulating hormone (TSH) were measured in plasma of all newborns three days after birth.

RESULTS

All newborns had concentrations of TSH within the range of normal reference values (<25 mU/l). Dichlorodiphenyl dichloroethylene (p,p'DDE), beta-hexachlorocyclohexane (beta-HCH), polychlorinated biphenyl (PCB) 138 and 118 were related to higher concentrations of TSH, although only significant for beta-HCH. Levels of HCB were not associated with TSH.

CONCLUSIONS

Although this community is highly exposed to HCB, no association was found between this organochlorine and TSH concentrations at birth.

Involvement of the kappa-opioid receptor in the anxiogenic-like effect of CP 55,940 in male rats

We have studied the possible interaction between three selective opioid-receptor antagonists, nor-binaltorphimine (NB: kappa) (5 mg/kg), cyprodime (CY: mu) (10 mg/kg) and naltrindole (NTI: delta) (1 mg/kg), and the cannabinoid receptor agonist CP 55,940, in the modulation of anxiety (plus-maze) and adrenocortical activity (serum corticosterone levels by radioimmunoassay) in male rats. The holeboard was used to evaluate motor activity and directed exploration. CP 55,940 (75 microg/kg, but not 10 microg/kg) induced an anxiogenic-like effect, which was antagonised by NB. The other effects of CP 55,940 (75 microg/kg), a decreased holeboard activity and stimulation of adrenocortical activity, were not antagonised by any of the three opioid receptor antagonists. CY and NTI, when administered alone, induced marked reductions in motor activity, anxiogenic-like effects and stimulation of adrenocortical activity. The selective kappa-opioid receptor antagonist NB, on its own, did not modify the level of anxiety but stimulated adrenocortical activity. We provide the first pharmacological evidence about the involvement of the kappa-opioid receptor in the anxiogenic-like effect of CP 55,940.

Trunk control test as a functional predictor in stroke patients

The purpose of this study was to evaluate prospectively the Trunk Control Test (TCT) correlation at admission to rehabilitation with length of stay, functional independence measure (FIM), gait velocity, walking distance and balance measured at discharge in 28 hemiparetic patients. FIM and TCT were registered on admission. Outcome measures at discharge were: FIM, gait velocity, walking distance and balance assessed with the Berg Balance Scale and computerized posturography. TCT was significantly correlated with length of stay (r = -0.722), discharge FIM (r = 0.738), discharge motor FIM (r = 0.723), gait velocity (r = 0.654), walking distance (p = 0.003), centre of gravity symmetry r = 0.601) and Berg Balance Scale (r = 0.755). Initial TCT predicts the 52% of the variation in length of stay and 54% in the discharge FIM. The predictive value of a compound variable (TCT and admission FIM) reaches 60% of the variation in length of stay and 66% in the FIM at discharge.

Advances in the chemistry and pharmacology of ecteinascidins, a promising new class of anti-cancer agents

Ecteinascidins are marine natural products consisting of two or three linked tetrahydroisoquinoline subunits and an active carbinolamine functional group. Their potent antiproliferative activity against a variety of tumor cells has made them attractive candidates for development as anticancer agents. The lead compound, ecteinascidin 743 (ET 743), is currently in phase II clinical trials but the low amounts present in its natural source, the tunicate Ecteinascidia turbinata, made it necessary to develop efficient synthetic procedures. Recent improvements on the original synthesis are reviewed as well as new strategies starting from readily available cyanosafracin B. ET 743 is known to bind to the minor groove of DNA giving rise to a covalent adduct with the exocyclic amino group at position 2 of a guanine in a fashion similar to saframycin antibiotics. Some of the resulting complexes have been studied by a variety of biochemical and spectroscopic methods and also by computer simulations. The rules for sequence specificity have been well established (preferred targets are RGC and YGG, where R and Y stand for purine and pyrimidine, respectively), and it has been shown that binding of ET 743 to DNA is accompanied by minor groove widening and DNA bending towards the major groove. Although the precise target for antitumor action remains to be unambiguously defined, a role in affecting the transcriptional regulation of some inducible genes is rapidly emerging.

Levels of hexachlorobenzene and other organochlorine compounds in cord blood: exposure across placenta

Hexachlorobenzene (HCB) is an organochlorine compound widespread in the environment, highly lipophilic, that accumulates in biological systems. It has been suggested that it should be classified as a dioxin-like compound. Newborns are exposed to organochlorine compounds across the placenta and through breastfeeding. Although HCB is one of the most common organochlorine compounds, the transplacental transference of HCB from mother to fetus during pregnancy has been scarcely documented. This study reports the levels of HCB, dichlorodiphenyl trichloroethane (DDT) and its metabolite p,p'DDE, polychlorinated biphenyls (PCBs), and beta-hexachlorocyclohexane (beta-HCH) in 72 maternal blood samples at delivery and in 69 cord blood samples, from which 62 corresponded to mother infant pairs born between May 1997 and September 1999 in a rural area highly exposed to HCB. Results show that all newborns presented detectable levels of HCB, PCBs, and p,p'DDE, and, to a lesser extent, of beta-HCH, the HCB levels being the highest. The geometric mean of HCB was 1.1 ng/ml, ranging from 0.3 to 5.7 ng/ml. Concentrations of HCB levels in cord blood (log ng/ml) were positively associated with concentrations in maternal blood (log ng/ml) (coefficient = 0.45, P < 0.01). Gestational age was not associated with the transplacental transfer of HCB. Maternal p,p'DDE and beta-HCH levels were also associated with newborn levels, but levels of PCBs were not. We conclude that HCB, similar to other organochlorinated compounds, has a transplacental transfer.

Changes in carboxysome structure and grouping and in photosynthetic affinity for inorganic carbon in Anabaena strain PCC 7119 (Cyanophyta) in response to modification of CO2 and Na+ supply

In ANABAENA: PCC 7119 a 4-fold decrease in the value of the apparent photosynthetic affinity for external inorganic carbon [K1/2 (Ci)] occurred between 9 and 12 h after the transfer from high-CO2 (2% CO2-enriched air) to air-growing conditions. A slight increase in carboxysome frequency occurred, but during this transition their appearance and distribution remained unchanged. ANABAENA: PCC 7119 did not improve its K1/2 (Ci) beyond the above cited level of acclimation neither by culturing the cyanobacteria in Na+-deficient medium in air nor by aeration with CO2-depleted air. In air-grown cultures, Na+ deficiency induced a large increase in carboxysome frequency and an alteration of their appearance: the greatest proportion were electron-dense whereas this type constituted a minority in high-CO2 and in air, Na+-sufficient conditions. It also induced major changes in carboxysome distribution, whereby more than 60% were grouped, compared with only 10% in high-CO2 and in air, Na+-sufficient conditions. These changes in carboxysome expression were extremely rapid, occurring mainly during the first 2 h.

Porcine dermatitis and nephropathy syndrome in Spain

In August 1995, the first case of porcine dermatitis and nephropathy syndrome was diagnosed in the north-eastern part of Spain; the pig showed characteristic dermal and renal lesions. Between then and January 1996, nine further animals from five different herds were diagnosed; they showed signs of anorexia, depression and, sometimes, pyrexia. Diarrhoea, Glässer's disease, conjunctivitis and gastric ulcers also occurred on the farms where the diagnoses were made. The affected pigs died of renal failure with diffuse fibrinous glomerulonephritis and a systemic necrotising vasculitis. Chronic interstitial nephritis, glomerulosclerosis and scar-like marks on the skin were observed in chronic cases. Other common findings in both acute and chronic cases were a diffuse depletion of lymph node lymphocytes with infiltration by syncytial cells (50 per cent of cases) and interstitial pneumonia. All the animals tested positive for porcine reproductive and respiratory syndrome virus (PRRSV) by serological tests and virus isolation. Serum urea and creatinine concentrations were above normal in the acutely affected animals. The pathogenesis of the condition is unknown but the lesions and immunopathological observations by other authors suggest that a type III hypersensitivity is a possible aetiology. The occurrence of PRRSV in these pigs suggests that the virus might be implicated in the pathogenesis of porcine dermatitis and nephropathy syndrome.

[Chylopericardium after acute pericarditis]

We present an 18 year-old man with chylopericardium after acute pericarditis with severe pericardial effusion and cardiac tamponade secondary to Mycoplasma pneumoniae infection. We review the etiology, diagnostic procedures and therapeutic possibilities for chylopericardium.

Biogenesis and Ultrastructure of Carboxysomes from Wild Type and Mutants of Synechococcus sp. Strain PCC 7942

Immature inclusions representing three progressive steps of carboxysome biogenesis have been identified in Synechococcus during the period of adaptation to low-CO2 conditions: (a) ring-shaped structures, (b) electron-translucent inclusions with the shape of a carboxysome and the internal orderly arrangement of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) molecules, and (c) carboxysomes with an internal electron-translucent area, which seem to be the penultimate stage of carboxysome maturation. The ability to build up normal carboxysomes is impaired in three (M3, EK6, and D4) of four high-carbon-requiring mutants studied in this work. M3 and EK6 exhibit abundant immature electron-translucent carboxysomes but no mature ones. This finding supports the contention that an open reading frame located 7.5 kb upstream of the gene encoding the large subunit of Rubisco (altered in M3) is involved in the carboxysome composition and confirms the structural role of the small subunit of Rubisco (slightly modified in EK6) in the assembly of these structures. D4 shows few typical carboxysomes and frequent immature types, its genetic lesion affecting the apparently unrelated gene encoding a subunit of phosphoribosyl aminoamidazole carboxylase of the purine biosynthesis pathway. Revertants EK20 (EK6) and RK13 (D4) have normal carboxysomes, which means that the restoration of the ability to grow under low CO2 coincides with the proper assembling of these structures. N5, a transport mutant due to the alteration of the gene encoding subunit 2 of NADH dehydrogenase, shows an increase in the number and size of carboxysomes and frequent bar-shaped ones.

A gene (ccmA) required for carboxysome formation in the cyanobacterium Synechocystis sp. strain PCC6803

A high-CO2-requiring mutant, G7, of Synechocystis sp. strain PCC6803 capable of inorganic carbon transport but unable to utilize the intracellular inorganic carbon pool for photosynthesis was isolated. Transmission electron micrographs of the mutant indicated that the mutant does not have any carboxysomes. A clone (pHPG7) with a 7.5-kbp DNA insert that transforms the G7 mutant to the wild-type phenotype was isolated from a genomic library of wild-type Synechocystis sp. strain PCC6803. Complementation tests with subclones identified the mutation site in G7 within 208 bp. Sequencing of nucleotides in this region elucidated an open reading frame, designated ccmA, encoding a protein of 302 amino acids. Cloning and sequence analysis of the respective G7 gene revealed an A-to-G substitution that results in an Asp-to-Gly substitution in the deduced amino acid. The result indicated that the ccmA gene encodes a protein essential for the formation of carboxysomes. An open reading frame encoding a proline-rich protein of 271 amino acids was found downstream of the ccmA gene, but no ccm-like genes or rbc operon was found in this region.

Inactivation of ccmO in Synechococcus sp. Strain PCC 7942 Results in a Mutant Requiring High Levels of CO 2

Inactivation of ccmO in Synechococcus sp. strain PCC 7942 resulted in a mutant which possesses aberrant carboxysomes and a normal inorganic carbon uptake capability but a reduced ability to photosynthetically utilize the internal inorganic carbon pool. Consequently, it exhibits low apparent photosynthetic affinity for extracellular inorganic carbon and demands high levels of CO 2 for growth.

Structural brain abnormalities as indicators of vulnerability to schizophrenia

The literature on structural brain abnormalities in schizophrenia is examined to determine whether these abnormalities represent viable candidate markers of vulnerability to the disorder. A majority of studies agree in finding that schizophrenia patients as a group have significantly larger ventricles and smaller limbic brain structures than normal control subjects, but about 50 percent of patients fall within the range of control subjects on these measures. This result has been interpreted to suggest that structural abnormalities characterize only a subgroup of patients. However, given the substantial degree of normal variability in brain structure between families, the use of biologically unrelated individuals as controls is misleading. Studies that have compared schizophrenia patients with their unaffected first-degree relatives have found a much higher sensitivity rate for ventricular enlargement and reduced limbic volumes (i.e., 70%-100%). This high within-family sensitivity, together with evidence from meta-analytic reviews of a substantial relationship between ventricular enlargement and severity of illness, argues in favor of a continuous distribution of the brain pathology in schizophrenia and against a model in which the pathology characterizes only a subgroup of patients. The structural abnormalities observed in both younger and older patients have been found to be highly correlated with familial risk for schizophrenia and obstetric complications, suggesting that some part of the deviance may be present in the premorbid state and that it may reflect both genetic and environmental etiologic processes. The evidence for specificity of the deficits to schizophrenia is equivocal, but no study has yet compared the within-family sensitivities of morphological measures among the major psychiatric conditions. Additional studies using first-degree relatives and well-defined neuroanatomical measurements are needed to determine which brain regions have the highest sensitivities as indicators of schizophrenia in families.

High CO2 concentration alleviates the block in photosynthetic electron transport in an ndhB-inactivated mutant of Synechococcus sp. PCC 7942

The high-concentration CO2-requiring mutant N5 of Synechococcus sp. PCC 7942 was obtained by the insertion of a kanamycin-resistant gene at the EcoRI site, 12.4 kb upstream of rbc. The mutant is unable to accumulate inorganic carbon internally and exhibits very low apparent photosynthetic affinity for inorganic carbon but a photosynthetic Vmax similar to that of the wild type. Sequence and northern analyses showed that the insertion inactivated a gene highly homologous to ndhB, encoding subunit II of NADH dehydrogenase in Synechocystis sp. PCC 6803 (T. Ogawa [1991] Proc Natl Acad Sci USA 88: 4275-4279). When the mutant and the wild-type cells were exposed to 5% CO2 in air, their photosynthetic electron transfer capabilities, as revealed by fluorescence and thermoluminescence measurements, were similar. On the other hand, a significant decrease in variable fluorescence was observed when the mutant (but not the wild-type) cells were exposed to low CO2 under continuous light. The same treatment also resulted in a shift (from 38-27 degrees C) in the temperature at which the maximal thermoluminescence emission signal was obtained in the mutant but not in the wild type. These results may indicate that subunit II of NADH dehydrogenase is essential for the functional operation of the photosynthetic electron transport in Synechococcus under low but not high levels of CO2. We suggest that the inability to accumulate inorganic carbon under air conditions stems from disrupture of electron transport in this mutant.

A Cyanobacterial Gene Encoding Peptidyl-Prolyl cis-trans Isomerase

The rotA gene encoding peptidyl-prolyl cis-trans isomerase has been identified, sequenced, and shown to be transcribed in the cyanobacterium Synechococcus sp. PCC7942. Inactivation of the gene by replacement of a region containing the open reading frame with a gene conferring kanamycin resistance resulted in merodiploids containing both the wild type and the modified genomic region. We were not able to isolate a kanamycin-resistant mutant in which all the genomic wild-type copies were substituted, which suggests that such replacement could have been lethal.

[Familial childhood cortical hyperostosis]

We present three cases of Caffey's disease, which have been observed in a family and a previous one former generation of the same family. A review of the literature upon family cases is carried out (35 families with 143 patients) prevailing the hypothesis of the type of autosomal dominant trait with incomplete penetrance and variable expressivity. HLA system is studied in such a family without common haplotypes being found and therefore the trait does not seem to be linked to genes of this system.

The turnover rate of gamma-aminobutyric acid in the nuclei of telencephalon: implications in the pharmacology of antipsychotics and of a minor tranquilizer

The turnover rate of GABA is measured in substantia nigra, globus pallidus, N. accumbens, and striatum of rats injected with muscimol, a potent GABA agonist, and diazepam. The similarity of action of the two drugs on GABA turnover further supports the theory that diazepam acts as a GABA-mimetic drug. Haloperidol and clozapine affect GABA turnover differently in different nuclei. Haloperidol decreases GABA turnover in caudate but does not affect that in substantia nigra, whereas clozapine increases GABA turnover in both areas. However, both drugs accelerate GABA turnover in globus pallidus and N. accumbens. It is suggested that an increase of GABA turnover and perhaps of GABA release in striatum and substantia nigra may account for the lack of tardive dyskinesia and extrapyramidal side effects of clozapine.