Life-threatening hyperkalaemia developing following excessive ingestion of orange juice in a patient with baseline normal renal function.

Hyperkalaemia is a less-recognised life-threatening cause of paralysis. We describe a 51-year-old African-American man, who suffered from muscle weakness progressing to ascending symmetric paralysis, and inability to masticate. Physical examination revealed flaccid paralysis with areflexia of the four limbs. Computed tomography of the brain and cervical spine did not demonstrate any organic lesions. Laboratory investigations revealed serum potassium 9.0 mEq/L (not haemolysed), blood urea nitrogen 34 mg/dL, and serum creatinine 2.0 mg/dL. Electrocardiography showed typical features of hyperkalaemia. After emergent treatment for hyperkalaemia was initiated, serum potassium was rapidly-normalised to 5 mEq/L and all neuromuscular symptoms reversed within one hour. Upon reviewing his food and medication history, he admitted drinking 2.5 litres of orange juice (which contains about 450 mg of potassium in 1,000 ml) per day for the past three weeks to quench his thirst. Hyperkalaemia should be borne in mind in the differential diagnosis of acute paralysis. Hidden sources of potassium intake, such as orange juice, should not be overlooked, even in patients with baseline normal renal function.

Production and characterization of monoclonal antibodies to E1 Tor toxin co-regulated pilus of Vibrio cholerae.

Murine monoclonal antibodies (MAbs) against Vibrio cholerae toxin co-regulated pilus (TCP) were generated using conventional hybridoma procedures. Four hybridomas were obtained and two characterized. Hybridomas 10E10E1 and 4D6F9 secreted antibodies of the IgG2a and IgG1 isotypes, respectively, that reacted with a 24-kDa antigen corresponding to the product of the El Tor tcpA gene fused to a six Histidine tail. Additionally, MAbs produced by 4D6F9 selectively recognized the major pilin subunit (TcpA) of El Tor and O139 vibrios in western immunoblot, while MAbs from 10E10E1 also cross-reacted with classical TcpA. Furthermore, vibrios expressing TCP on their surface selectively inhibited binding of the antibodies secreted by both hybridomas to TcpA-coated microtiter plates. Thus, the MAbs reported in this work detected the structural subunit of the pilus either denatured or assembled on the bacterial surface.

Construction and characterization of a nonproliferative El Tor cholera vaccine candidate derived from strain 638.

In recent clinical assays, our cholera vaccine candidate strain, Vibrio cholerae 638 El Tor Ogawa, was well tolerated and immunogenic in Cuban volunteers. In this work we describe the construction of 638T, a thymidine auxotrophic version of improved environmental biosafety. In so doing, the thyA gene from V. cholerae was cloned, sequenced, mutated in vitro, and used to replace the wild-type allele. Except for its dependence on thymidine for growth in minimal medium, 638T is essentially indistinguishable from 638 in the rate of growth and morphology in complete medium. The two strains showed equivalent phenotypes with regard to motility, expression of the celA marker, colonization capacity in the infant mouse cholera model, and immunogenicity in the adult rabbit cholera model. However, the ability of this new strain to survive environmental starvation was limited with respect to that of 638. Taken together, these results suggest that this live, attenuated, but nonproliferative strain is a new, promising cholera vaccine candidate.

Endocrine profile in a patient with familial breast cancer: a case-control study.

Urinary and blood hormonal profiles were studied throughout a monthly cycle in a patient with familial breast cancer. Two comparison cohorts (one high-risk and one low-risk) were studied concurrently. Findings disclosed that our breast cancer-affected patient showed a distinctive hormonal pattern characterized by significant elevation throughout the cycle of plasma estrone, estradiol, and prolactin. Save for a depression in plasma FSH in the early follicular phase, this hormone, as wells as LH and progesterone patterns in our patient, were similar to the comparison cohorts. Urinary estrone and estradiol patterns in our patient were elevated early in the follicular phase. Our patient also showed a depression in urinary estrone, estradiol, and estriol following ovulation, which persisted throughout the luteal phase. Blood and urinary hormone patterns in the high-risk cohort were not demonstrably different from the low-risk cohort, with the exception of plasma prolactin. The results on the latter hormone showed an unexpected significant depression throughout most of the menstrual cycle in this low-risk cohort. We conclude that estrone and estradiol elevations, as clearly evidenced in our breast-cancer-affected patient, may provide clues that ultimately might be used as an etiologic discriminant for breast cancer risk and which may also play a pathogenic role in this disease. Since this involved a single patient, our conclusions must be interpreted cautiously.