Expression of the Human Immunoglobulin Heavy Chain VH6 Gene Element by Fetal B Lymphocytes

Fetal B lymphocytes in mice and humans use a limited number of the available V_H gene segments. Mouse fetal B cells primarily utilize 3' V_H elements, suggesting that the localization of these elements determines their rearrangement frequency. The previously reported non-random usage of human V_H genes has been more difficult to explain. In this study the authors analysed the expression of the most proximal 3' human V_H element (V_H6) using a monoclonal antibody (JE-6). V_H6 expression was assessed in various B cell differentiation stages from fetal liver, bone marrow and spleen at 12–20 weeks of gestation. The authors demonstrate that the level of V_H6 expression does not exceed a stochastic usage frequency. This suggests that the localization of V_H6 does not significantly promote its expression during human fetal life, and that other factors must affect the usage of V_H genes during human fetal development.     

Spleen sizing by ultrasound in polycythaemia and thrombocythaemia: comparison with SPECT

Detection of non-palpable early splenic enlargement may aid diagnosis of primary polycythaemia (PP) and primary thrombocythaemia (PT). In this study linear spleen sizing by ultrasound has been compared with spleen volume estimation by single photon emission computerized tomography (SPECT) in 26 patients. Spleen length by ultrasound correlated well with SPECT volume estimation.
Ultrasound spleen length was also measured in 60 normal control subjects where the upper limit of the 95% reference range was 11.6 cm. Changes in spleen length with both age and body weight were substantial and overshadowed the imperfect reproducibility of this method. Therefore, interpretation of an individual's measured spleen length should be in relation to that predicted for adults of the same age and weight, particularly at the extremes of the younger, heavier patients and also the older, lighter patients.
Ultrasound spleen lengths of different patient groups (21 PP, 26 PT, 17 idiopathic erythrocytosis, 12 secondary polycythaemia, nine apparent polycythaemia) were compared both using the measured overall reference range and the differences from the values predicted for their age and weight. The comparison showed that almost all patients with PP whose spleens were not palpable had spleen lengths greater than the upper limit for the normal control group, but separation from the other patient groups was incomplete.
Detection of non-palpable splenomegaly by ultrasound length should remain a 'minor' criterion amongst the 'proposed modified diagnostic criteria' of PP.     

Evidence for the presence of a type III secretion system in diffusely adhering Escherichia coli (DAEC).

Diffusely adhering Escherichia coli (E. coli) strains (DAEC) represent a potential cause of diarrhoea in infants, and the detection of type three secretion system (TTSS) genes in DAEC would substantiate their pathogenic nature. In this work, four isolates of DAEC, recovered from stools of diarrhoeic children, were analysed by PCR, in order to detect the presence of TTSS genes. Primers targeted to the escC, escJ, escN and escV, some of the most conserved TTSS genes in enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC and EHEC), were used in order to verify the occurrence of homologous genes in our DAEC isolates. By this approach, we were able to characterise DNA fragments corresponding to putative escJ and escN genes in all DAEC isolates. Furthermore, DNA fragments homologous to the escC and escV genes were also amplified from all isolates. Besides the similarity found among the DAEC esc homologues with EPEC and EHEC esc genes, the nucleotide sequence analysis of the flanking regions of the amplified DNA fragments suggests that the putative DAEC esc genes are organised in the same manner as observed in EPEC and in EHEC strains. The results described here provide strong evidence for the presence of a TTSS in the DAEC strains analysed, implicating a pathogenic nature of these isolates.     

Occupational exposure to hazardous substances and risk of cancer in the area of the mouth cavity, oropharynx, hypopharynx and larynx. A case-control study

A case-control study of squamous cell carcinoma of the upper aerodigestive tract conducted in Heidelberg and Giessen (FRG) provided information on occupational factors in 200 patients and 800 controls (adjusted to sex, age and area of living; 4:1 matched design). The number of subjects exposed to wood dusts, organic chemicals, coal products or to cement was significantly elevated in the tumour group. An increased risk for head and neck cancer was observed after exposition to wood dust (RR = 2,2), organic compounds (RR = 2,4), coal products (RR = 2,7) and especially to cement (RR = 4,4). The cancer risk due to cement exposition showed a positive correlation to the duration of exposition and remained significantly elevated after adjustment for alcohol and tobacco consumption.     

Prior immunologic experience potentiates the subsequent antibody response when Salmonella strains are used as vaccine carriers.

Prior immunologic experience with homologous and heterologous serotype Salmonella strains potentiated the subsequent antibody response when the same strains were used as vaccine carriers of foreign antigens. This potentiation was positively correlated with the appearance of antibody directed against the lipopolysaccharide of the carrier strain. Both serum and mucosal antibody responses against the foreign antigen increased over time. Antibody responses in sera of animals primed with either the homologous or heterologous serotype strain were not statistically significantly different, while animals primed with the homologous serotype strain developed significantly better mucosal antibody responses against the foreign antigen.     

Effect of maternal administration of thyrotropin-releasing hormone or DN1417 on functional and morphologic fetal rabbit lung maturation and duration of survival after premature delivery

Though maternal treatment with thyrotropin-releasing hormone (TRH) for prevention of hyaline membrane disease has been utilized, precise mechanisms of TRH in accelerating fetal lung maturation remain unclear. We studied the effect of maternally administered TRH or DN1417 (an analog of TRH) on functional and morphologic fetal rabbit lung maturation and the duration of survival after premature delivery. Because DN1417 retains the neurotransmitter but not the neuroendocrine effects of TRH, this study enables us to determine which of these effects was responsible for enhancement of lung maturation. TRH or DN1417 (0.2 mg/kg/dose) or saline was injected intravenously into New Zealand White rabbit does 48, 36, 24, 12 and 2 h prior to sacrifice on day 27 of gestation. Functional pulmonary maturity was assessed by pressure-volume hysteresis, and morphologic maturity was assessed by histologic technique. Maternal administration of TRH or DN1417 enhanced both functional and morphologic fetal lung maturation as well as the duration of neonatal survival after premature delivery. We propose that the effect of TRH in fetal lung maturation is due to neurotransmitter rather than neuroendocrine effects.     

Fronto-ethmoidal mucocoeles: a histopathological analysis.

From a series of 118 fronto-ethmoidal mucocoeles, 40 specimens have been submitted to detailed histological analysis. The frequency of each epithelial and sub-epithelial component is considered and reveals features which support a dynamic theory of bone resorption and formation rather than that of pressure erosion in the pathogenesis of mucocoeles.     

Facial reanimation after acoustic neuroma excision: the patient's perspective

Facial reanimation after acoustic neuroma excision is currently accomplished using a variety of surgical techniques. A multi-institutional survey of patient perceptions of facial reanimation success was accomplished by mailing a questionnaire to 809 randomly selected members of the Acoustic Neuroma Association. Four hundred sixty patients who underwent 296 reanimation procedures responded. Facial to hypoglossal nerve anastomosis, tarsorrhaphy, and upper eyelid implants were most frequently performed. The patient's estimations of initial deficit, spontaneous recovery, and overall satisfaction with the reanimation procedures are discussed.     

Biting in day care centers: incidence, prevention, and intervention.

Analysis of accident logs in child day care centers indicates that biting is common, especially among toddlers 13 to 30 months of age. Children of this age often lack appropriate verbal skills and resort to aggressive means to achieve their goals. Still awkward in gross-motor skills, toddlers can also suffer self-bites following accidental falls. According to medical reports, human bites sometimes are more virulent than animal bites and can cause severe trauma. Although the AIDS virus has been cultured from saliva, transmission from saliva alone has not been documented. Bite injuries in day care, however, usually are minor and can be treated by washing, applying cold compresses, and comforting the child. Suggested methods to diminish the frequency of biting in day care include physical changes within the room, behavior modification, and other classroom management techniques.