Severe Megaloblastic Anaemia in an Infant

Vitamin B 12 or cobalamin deficiency, a rare clinical entity in pediatric age, is found most exclusively in breastfed infants, whose mothers are strictly vegetarian non-supplemented or with pernicious anaemia. In this article, the authors describe a 10-month-old infant admitted for vomiting, refusal to eat and prostration. The infant was exclusively breastfed and diffi culties in introduction of new foods were reported. Failure to thrive since 5 months of age was also noticed. Laboratory evaluation revealed severe normocytic normochromic anaemia and cobalamin defi cit. A diagnosis of α-thalassemia trait was also made. Maternal investigation showed autoimmune pernicious anaemia. This case shows the severity of vitamin B 12 deficiency and the importance of adopting adequate and precocious measures in order to prevent potentially irreversible neurologic damage.

Incontinentia Pigmenti in the Neonatal Period

Incontinentia pigmenti (IP) is a rare multisystem disease, X linked dominant disorder. As all X linked dominant diseases, it is usually male-lethal. Female newborn admitted to the neonatal intensive care unit on the fi rst day of life was diagnosed as having probable herpetic infection with vesicular skin lesions distributed on upper right limb and inferior limbs. Family history showed that her 22-year-old mother had hypopigmented lesions on the lower limbs and her 13-month-old sister had hyperpigmented lesions on the trunk and limbs. In newborns, herpes infection emerges as the principal diagnosis of vesicular rash, due to the importance of precocious diagnosis and treatment. Other hypothesis must be considered in a newborn with vesicobullous rash, such as IP.

Acquired-Transient Factor X Deficiency in a Teenager with Extensive Burns

Acquired factor X deficiency is an extremely rare situation. It has shown to be associated with systemic amyloidosis, respiratory mycoplasma infection, factor X inhibitors, antiphospholipid antibodies, vitamin K defi ciency/liver disease as well as the use of certain medications (meropenem, valproic acid). The pathogenesis and transient nature of this deficit remain poorly understood. The authors describe the case of a teenager hospitalised for extensive burns that developed active bleeding after removal of central venous catheter. He was diagnosed with transient factor X deficiency. Normalisation of coagulation status and factor X levels occurred spontaneously 10 days after the bleeding episode.

The Role of the Humoral Immune Response in the Molecular Evolution of the Envelope C2, V3 and C3 Regions in Chronically HIV-2 Infected Patients

BACKGROUND: This study was designed to investigate, for the first time, the short-term molecular evolution of the HIV-2 C2, V3 and C3 envelope regions and its association with the immune response. Clonal sequences of the env C2V3C3 region were obtained from a cohort of eighteen HIV-2 chronically infected patients followed prospectively during 2-4 years. Genetic diversity, divergence, positive selection and glycosylation in the C2V3C3 region were analysed as a function of the number of CD4+ T cells and the anti-C2V3C3 IgG and IgA antibody reactivity RESULTS: The mean intra-host nucleotide diversity was 2.1% (SD, 1.1%), increasing along the course of infection in most patients. Diversity at the amino acid level was significantly lower for the V3 region and higher for the C2 region. The average divergence rate was 0.014 substitutions/site/year, which is similar to that reported in chronic HIV-1 infection. The number and position of positively selected sites was highly variable, except for codons 267 and 270 in C2 that were under strong and persistent positive selection in most patients. N-glycosylation sites located in C2 and V3 were conserved in all patients along the course of infection. Intra-host variation of C2V3C3-specific IgG response over time was inversely associated with the variation in nucleotide and amino acid diversity of the C2V3C3 region. Variation of the C2V3C3-specific IgA response was inversely associated with variation in the number of N-glycosylation sites. CONCLUSION: The evolutionary dynamics of HIV-2 envelope during chronic aviremic infection is similar to HIV-1 implying that the virus should be actively replicating in cellular compartments. Convergent evolution of N-glycosylation in C2 and V3, and the limited diversification of V3, indicates that there are important functional constraints to the potential diversity of the HIV-2 envelope. C2V3C3-specific IgG antibodies are effective at reducing viral population size limiting the number of virus escape mutants. The C3 region seems to be a target for IgA antibodies and increasing N-linked glycosylation may prevent HIV-2 envelope recognition by these antibodies. Our results provide new insights into the biology of HIV-2 and its relation with the human host and may have important implications for vaccine design.

Enterobacteriaceae ISOLATES FROM THE ORAL CAVITY OF WORKERS IN A BRAZILIAN ONCOLOGY HOSPITAL

The evaluation of workers as potential reservoirs and disseminators of pathogenic bacteria has been described as a strategy for the prevention and control of healthcare-associated infections (HAIs). The aim of this study was to evaluate the presence of Enterobacteriaceae in the oral cavity of workers at an oncology hospital in the Midwest region of Brazil, as well as to characterize the phenotypic profile of the isolates. Saliva samples of 294 workers from the hospital’s healthcare and support teams were collected. Microbiological procedures were performed according to standard techniques. Among the participants, 55 (18.7%) were colonized by Enterobacteriaceae in the oral cavity. A total of 64 bacteria were isolated, including potentially pathogenic species. The most prevalent species was Enterobacter gergoviae (17.2%). The highest rates of resistance were observed for β-lactams, and 48.4% of the isolates were considered multiresistant. Regarding the enterobacteria isolated, the production of ESBL and KPC was negative. Nevertheless, among the 43 isolates of the CESP group, 51.2% were considered AmpC β-lactamase producers by induction, and 48.8% were hyper-producing mutants. The significant prevalence of carriers of Enterobacteriaceae and the phenotypic profile of the isolates represents a concern, especially due to the multiresistance and production of AmpC β-lactamases.

Structural and functional studies of PpcA: a key protein in the electron transfer pathways of Geobacter sulfurreducens

Dissertação para obtenção do Grau de Doutor em Bioquímica, ramo de Biotecnologia

Multiple Haemangiomas, Diaphragmatic Eventration and Beckwith-Wiedemann Syndrome: An Unusual Association

A 6-month-old girl with Beckwith-Wiedemann syndrome, multiple haemangiomas (axillary, laryngeal, pulmonary and hepatic) and diaphragmatic eventration was reported. All tumours responded to treatment with propranolol. The surgical correction of diaphragmatic eventration was crucial to a better outcome.

Rickettsial Infection Caused by Accidental Conjunctival Inoculation

The most common transmission route of tick-borne Rickettsia is through tick bite; nevertheless, other transmission routes should also be considered. We report a case of rickettsial infection in a 15-year-old boy caused by accidental contamination of the conjunctiva through the infected fluid of a crushed engorged tick removed from a dog. Right eye pain, conjunctival hyperaemia with mucopurulent exudate, chemosis and eyelid oedema were the first signs and symptoms. Two days later, the boy developed fever, myalgia, headache, abdominal pain and was vomiting; physical examination showed multiple cervical adenopathies but no rash. He was treated with doxycycline (200 mg/day) for 7 days with progressive resolution of clinical signs. Rickettsial infection was confirmed by immunofluorescence assay with serological seroconversion in two consecutive samples. Rickettsia conorii or Rickettsia massiliae were the possible causal agents since they are the Rickettsia spp found in the Rhipicephalus sanguineus dog tick in Portugal.

Implant Site Nexplanon Reaction?

Nexplanon (Schering-Plough Limited/Merck Sharp & Dohme Limited (MSD)) is a long active reversible contraceptive method that provides effective contraception for 3 years. It consists of a single, flexible, rod-shaped implant, containing 68 mg etonogestrel. It is 4 cm long, consists of an ethylene vinyl acetate copolymer, a non-absorbable material, and also contains 15 mg of barium sulfate, which makes it visible by X-ray. We describe a case of a 39-year-old woman who experienced a local reaction to the barium sulfate in Nexplanon. She was given medical treatment, but only the removal of the implant resolved the symptoms. After removal there was gradual improvement and 72 h later the patient was asymptomatic. Allergic reaction to barium sulfate is extremely rare: until now, there have only been two cases associated with Nexplanon described in the literature.

Acute Sheehan's Syndrome Presenting as Central Diabetes Insipidus

Sheehan's syndrome occurs as a result of ischaemic pituitary necrosis due to severe postpartum haemorrhage. Improvements in obstetrical care have significantly reduced its incidence in developed countries, but postpartum pituitary infarction remains a common cause of hypopituitarism in developing countries. We report a case of severe postpartum haemorrhage followed by headache, central diabetes insipidus and failure to lactate, which prompted us to investigate and identify both anterior and posterior pituitary deficiency compatible with Sheehan's syndrome. A timely diagnosis allowed us to implement an adequate treatment and follow-up plan, which are known to improve clinical status and patient outcome.

Insights into Campylobacter jejuni Desulforubrerythrin catalytic mechanism

Dissertation presented to obtain the Master Degree in Molecular Genetics and Biomedicine