Selective interference with class I major histocompatibility complex presentation of the major immediate-early protein following infection with human cytomegalovirus

Responses of cytotoxic T-cells (Tc) to human cytomegalovirus (CMV) represent the predominant mechanism by which hosts resist CMV infection. The CMV major immediate-early protein (IE) is present throughout the virus replicative cycle. Studies were performed to determine whether Tc specific for IE effectively lyse CMV-infected targets and are thus capable of providing protective immunity against infection. After in vitro stimulation of peripheral blood mononuclear cells with CMV-infected autologous fibroblasts, Tc specific for IE were not readily detectable in CMV-reactive polyclonal Tc lines. However, after stimulation of peripheral blood mononuclear cells with cells selectively expressing IE, weak but detectable IE-specific Tc responses were observed. The frequency of IE-specific Tc clones derived from cultures stimulated with IE-expressing cells was 50 to 100 times lower than the frequency of Tc clones specific for other CMV proteins isolated from cultures stimulated with CMV-infected cells. All of the IE-specific Tc clones, which efficiently lysed targets selectively expressing IE, demonstrated minimal lysis of CMV-infected fibroblasts, despite abundant IE expression in these target cells. In contrast to these results with IE, other viral proteins were efficiently presented during all phases of CMV infection. These data suggest that CMV has evolved a unique mechanism for selectively limiting the presentation of the potentially immunogenic IE protein, which may preclude IE-specific Tc from providing protective immunity to CMV infection.     

Excessive scapular motion in individuals recovering from painful and stiff shoulders: causes and treatment strategies

BACKGROUND AND PURPOSE: Scapular excursion and the wrist speed were studied before and after instruction and practice designed to achieve symmetrical scapular movement. SUBJECTS: Subjects were 10 female and 6 male patients, aged 44 to 78 years (chi=60.3, SD=11.2), with diagnosed shoulder pathologies. METHODS: Subjects were videotaped performing a reaching task. Pain status was monitored. The subjects were instructed to make the scapular movement symmetrical. They then repeated the task, while being videotaped, to monitor the effect of instruction. RESULTS: Individuals with asymmetric upper-extremity starting positions had excessive vertical motion of the involved scapula, which they controlled after instruction. Peak wrist speed of the involved upper extremity was lower only after instruction. CONCLUSION AND DISCUSSION: Even in the absence of biomechanical factors or pain, excessive scapular vertical motion appears to occur in the involved upper extremities of individuals recovering from unilateral shoulder problems. Improved scapular control can follow simple verbal instruction and practice, with a slight decrement in wrist speed.     

Structural studies of the putative O-specific polysaccharide of Acinetobacter baumannii O2 containing 3,6-dideoxy-3-N-(D-3-hydroxybutyryl)amino-D-galactose

A polysaccharide containing D-galactose, 2-deoxy-2-N-acetylamino-D-galactose and 3,6-dideoxy-3-N-(D-3-hydroxybutyryl)amino-D-galactose, probably corresponding to the lipopolysaccharide side chain, was obtained from an aqueous phenol extract of isolated cell walls from Acinetobacter baumannii strain O2. By means of NMR studies and chemical degradations, the repeating unit of the polymer was identified as a branched hexasaccharide of the structure shown, where Fuc3N represents 3-amino-3,6-dideoxygalactose and R represents D-3-hydroxybutyryl. Serological tests indicated that the polymer corresponded to the O2 antigen.     

The prevalence of clinically significant anaemia and haemoglobinopathy in children requiring dental treatment under general anaesthesia: a retrospective study of 1000 patients

There is little information on the possible value of screening children who are liable to haemoglobinopathies as part of pre-operative assessment for dental treatment under general anaesthesia. The present retrospective investigation examined, first, the number of patients having low haemoglobin levels among 1000 patients who had undergone haematological investigation prior to general anaesthesia in a dental outpatient unit, and, secondly, the subsequent clinical management of these patients. Haemoglobin levels of 10.0 g/dl or less were found in 31 children: 13 Asian, 7 Afro-Caribbean, 5 Mediterranean, 3 Arabic, 1 white Caucasian and 2 Oriental children. In addition, 17 patients had sickle-cell trait and 2 had beta-thalassaemia trait, but there was no relationship between the presence of haemoglobinopathy and low levels of haemoglobin. The planned general anaesthesia was undertaken for 22 of the 31 children who had low levels of haemoglobin and for the 19 children with haemoglobinopathy. Only 6 children ultimately did not undergo general anaesthesia, all failing to return. It is concluded that pre-anaesthetic haematological assessment of children needing minor dental surgery is rarely of any significant clinical value.     

Cisapride reduces neonatal postoperative ileus: randomised placebo controlled trial

AIM: To assess the efficacy of cisapride in reducing ileus persisting to the tenth postoperative day after neonatal abdominal surgery. METHODS: A prospective, randomised, double blind trial comparing rectal cisapride (1.4-2.3 mg/kg/day) with placebo over seven days was undertaken in 33 neonates. RESULTS: Seven of 12 (58%) patients receiving placebo and eight of 11 (73%) receiving cisapride achieved a first sustained feed during treatment. Of those receiving cisapride, the first sustained feed occurred at 2.3 days (SEM 0.6) compared with 4.7 days (SEM 0.8) with placebo. By the seventh day the mean daily net enteral balance was 69 (SEM 18) ml/kg in the cisapride subgroup and 17 (SEM 8) ml/kg for those receiving placebo. Stool was passed on 6.3 (SEM 0.4) treatment days in the cisapride subgroup compared with 4.1 (SEM 1.0) treatment days in the placebo subgroup. CONCLUSION: Cisapride is effective in neonates with a prolonged ileus after abdominal surgery.     

Calcium phosphate/calcium oxalate crystal association in urinary stones: implications for heterogeneous nucleation of calcium oxalate

PURPOSE: Most stones contain more than one type of crystals, and some combinations, such as calcium phosphate/calcium oxalate, are more common than others. Epitaxy between the crystals has been suggested to play a role in growth of such stones. The specific aim of this study is to investigate the involvement of calcium phosphate in crystallization of calcium oxalate. MATERIALS AND METHODS: Twenty calcium oxalate stones or stone fragments were examined using various microscopic techniques, including scanning, transmission and back-scattered electron microscopy. Similarly, calcium oxalate stones induced on a plastic foreign body implanted inside urinary bladders of laboratory rats were also investigated. Examination of the interface between calcium phosphate and calcium oxalate crystals was emphasized. RESULTS: Close association between crystals of calcium phosphate and calcium oxalate were found in both the human and rat stones. All crystals examined were associated with an organic matrix on the surface and contained copious amounts of organic material within the crystalline entities. Interface between the crystals also appeared to be occupied by organic matrix. CONCLUSIONS: Results of this and other studies from our laboratory indicate that epitaxy between various crystals, even though theoretically possible, appears unlikely in vivo. The appearance of specific crystalline combinations in stones is probably a result of the urinary environment being conducive for crystallization of those components. Heterogeneous nucleation of calcium oxalate is most probably induced by biological elements, including membranous cellular degradation products.