Acute bacterial meningitis in children in Hefei, China 1990-1992

OBJECTIVE

To obtain etiologic and epidemiologic information about bacterial meningitis, especially the H influenza type B (Hib), from a medium-sized city, Hefei, China.

METHODS

Data were collected prospectively over 3 years, from 1990 to 1992 by a well-organized group including 13 hospitals. All children with a clinical diagnosis of acute bacterial meningitis were enrolled and the specimens were taken for the etiologic studies. CSF and blood were tested by standard bacteriologic technique. CSF, blood and concentrated urine were tested directly for detection of antigen by countercurrent immuno-electrophoresis (CIE). Data were analyzed by epidemiologic methods.

RESULTS

Bacterial culture and CSF Gram's staining were positive only in 13.3% and 11.7%, respectively. Bacterial antigen detection was positive in up to 90% by CIE which was more sensitive than bacterial culture (chi 2 = 67.7, P < 0.005). The annual incidence of acute bacterial meningitis in the city is calculated as 9.3 cases/100,000 children from 1 month to 15 years of age and 19.2 cases/100,000 children from 1 month to 5 years of age. Hib meningitis accounted for 51.7%, N. meningitis (Nm) for 38.3%, and S. pneumoniae (Sp) for 8.3%. There was no significant seasonal variation. Of the patients, 76.7% were children under 5 years of age, and 51.7% under 1 year of age. The case fatality rate was 11.7% for all bacterial meningitis, 9.7% for Hib, 17.4% for Nm and 20% for Sp. A total of 22.6% of survivors suffered from neurological or psychological problems.

CONCLUSIONS

Using antigen detection combined with bacterial culture, we could make an etiologic diagnosis in up to 90% of the patients in this group. Hib, Nm and Sp were the predominant pathogens, which was similar to the findings in other countries. Hib was the most common cause of bacterial meningitis, but the incidence was much lower than in most parts of the world.

[Navelbine as a single agent to treat advanced breast cancers]

From March 1994 to March 1995, 14 cases of refractory advanced breast cancers were treated with Navelbine (NVB). NVB as a single agent was given weekly 40-60mg (24.9mg-33.3 mg/m2), every 2 weeks for one cycle. Six of fourteen cases (42.9%) achieved partial response (PR). The median remission duration of PR patients was 5 months (range 2-10 months). NVB was given 85 times, the main side effects were myalgia and arthralgia (80.0%), phlebitis (57.6%). Sixty-five of eighty five pretreatment WBC counts were below 4.0 x 10(9)/L, and the severity of leukopenia was related to pretreatment WBC level. No patient died of infection.

Vascular malformations of the brain. Surgical management using interactive image guidance

This article describes the use of interactive image guidance in the surgical management of vascular malformations (VMs). Indications include VMs located in or around eloquent brain regions such as speech and motor sensory areas. The image guidance provides a three-dimensional view of the actual vascular malformations through computer simulation and an accurate means of determining its position in relation to adjacent brain structures (anatomic localization).

A calcium switch for the functional coupling between alpha (hslo) and beta subunits (KV,Ca beta) of maxi K channels

KV,Ca beta subunit dramatically increases the apparent calcium sensitivity of the alpha subunit of MaxiK channels when probed in the micromolar [Ca2+]i range. Analysis in a wide range of [Ca2+]i revealed that this functional coupling is exquisitely modulated by [Ca2+]i. Ca2+ ions switch MaxiK alpha+beta complex into a functionally coupled state at concentrations beyond resting [Ca2+]i. At [Ca2+] < or = 100 nM, MaxiK activity becomes independent of Ca2+, is purely voltage-activated, and its functional coupling with its beta subunit is released. The functional switch develops at [Ca2+]i that occur during cellular excitation, providing the molecular basis of how MaxiK channels regulate smooth muscle excitability and neurotransmitter release.

[Glutamine dipeptide enriched nutritional solutions attenuate bacterial translocation in rats after 60% intestinal resections]

OBJECTIVE

To investigate the effects of alanyl-glutamine dipeptide (Ala-Gln) enriched parenteral nutrition solution on intestinal mucosa or gut barrier since traditional parenteral nutrition leads to bacterial translocation.

METHODS

The moderate operation stress was induced by 60% resection of small intestine. Qualified rats distributed in three groups: Chow group (n = 10) received standard rat chow, PN group (n = 10) received traditional parenteral nutrition solution only, and Ala-Gln group (n = 10) received glutamine dipeptide enriched nutritional solutions (3% Ala-Gln). Rats were maintained on their respective diets for 7 days.

RESULTS

Chow group and Ala-Gln group maintained serum glutamine concentration, villus height and mucosal thickness. The bacterial translocation rate in Chow group and Ala-Gln group was 20% and in PN group 70%.

CONCLUSION

Results demonstrate that Ala-Gln enriched nutritional solutions maintain intestinal adaptation and gut barrier function after massive intestinal resection.

Effect of different chemically modified oligodeoxynucleotides on immune stimulation

Based on previous studies that certain oligonucleotides can stimulate cell proliferation and immunoglobulin production, this study was carried out to establish the relationship between the stimulatory effect and the chemical modification of the oligonucleotide. First, the effects of oligonucleotide and analogs on immune stimulation were studied in vitro using murine splenic lymphocytes. Our results show that cell proliferation and immunoglobulin production (IgG and IgM) depend on the sequence and the chemical modification of the oligonucleotide. Phosphorothioate oligodeoxynucleotides displayed a greater stimulatory effect than partially modified phosphorothioate oligonucleotides. Second, we studied the effects of these chemically modified oligonucleotides after injection in mice. Massive splenomegaly and stimulation of cell proliferation were observed with some phosphorothioate oligonucleotides. These effects were minimized markedly by chimeric and hybrid oligonucleotides. We also demonstrate that in vitro the effects of oligonucleotides on murine lymphocytes were unaffected by T cell depletion, suggesting that oligonucleotides exert their effects mainly on the B cells.

Loss of Rb and Myc activation co-operate to suppress cyclin D1 and contribute to transformation

Cyclin D1 can bind and phosphorylate the product (pRb) of the retinoblastoma gene (RB-1) and recent evidence suggests pRb, in turn, may regulate cyclin D1 protein expression. In transformed cell lines, loss of pRb activity strongly correlates with a decrease in cyclin D1 protein expression, and conversely, introduction of pRb can induce cyclin D1 promoter activity. We show here that pRb does not regulate cyclin D1 directly as basal and serum-stimulated levels of cyclin D1 protein and kinase activity are similar in wildtype and pRb-deficient primary mouse embryonic fibroblasts (MEFs). These observations suggest that the suppression of cyclin D1 in pRb-minus tumour cell lines requires both loss of pRb and at least one additional genetic event. We have determined that constitutive, ectopic Myc expression in pRb-deficient, but not wildtype, MEFs suppresses cyclin D1 protein expression and kinase activity. Regulation is evident at either the level of RNA or protein expression. Phenotypically, pRb-deficient MEFs consistently exhibited a delayed growth response in comparison to wildtype MEFs. This growth delay is abrogated in pRb-deficient MEFs which are expressing ectopic Myc protein, coincident with the loss of cyclin D1 protein expression. Moreover, these cells exhibit an increased proliferative capacity, and they no longer show contact inhibition. Our results support a cross-regulatory mechanism between Myc, pRb and cyclin D1 and suggest a novel role for cyclin D1 in tumorigenesis.

Image-guided computer-assisted spine surgery: a pilot study on pedicle screw fixation

As the pedicle offers a strong point of attachment to the spine, several instrumentation systems using screws that go through the pedicle into the vertebral body have been developed to provide internal stability. All pedicle screw systems share the risk of damage to adjacent neural structures as a result of improper screw placement. A computer-assisted system allowing precise preoperative planning and real-time intraoperative interactive image localization has been implemented for spine instrumentation to optimize transpedicular spine fixation. A validation study was performed in an in vitro set-up drilling 20 pedicle pilot holes in lumbar vertebrae. An analysis in 77 histological cuts showed an ideal location in 70 with no case of injury to the pedicle cortex. We discuss initial clinical experience on cases of posterior lumbar stabilization. Interactive computer-assisted spine surgery provides an accurate and safe approach for transpedicular screw fixation and may provide a useful tool for optimization of spine surgery.

Conserved regulatory element involved in the early onset of Hoxb6 gene expression

We have identified a 338 bp DNA fragment, the lateral plate mesoderm (LPM) enhancer, that is highly conserved between mouse and human. The LPM enhancer directs gene expression into the posterior lateral plate mesoderm and hindgut endoderm at early stages of development. By reporter gene analysis in transgenic mice, we demonstrate that both mouse and human DNA sequences possess similar enhancer activity. The expression patterns of the transgene and Hoxb6 during early stages of mouse development are identical, suggesting that the LPM enhancer is involved in the initial activation of Hoxb6 gene expression in posterior regions of mammalian embryos.

[A prospective randomized study of parenteral and enteral nutrition in postoperative patients]

To evaluate the metabolic effects of balanced enteral nutrition (EN) and standard parenteral nutrition (PN, without glutamine) in post-operative patients, we performed a prospective randomized trial in 24 patients after gastrectomy or semi-colectomy. All patients had normal liver, kidney, heart and lung functions. patients of the enteral nutrition group received liquid Ensure (Abbott-Ross) while patients of the parenteral nutrition group received standard parenteral nutrition. Parenteral nutrition solutions consist of amino acids, fat emulsions, glucose, electrolytes, vitamins and trace elements. Subjects of the two groups received iso-nitrogenous and isocaloric nutritional regime for seven days (from POD+5 to POD+11). Weight loss in the parenteral nutrition group and the enteral nutrition group was 1.7 +/- 0.2 kg and 0.8 +/- 0.31 kg respectively. Cumulative nitrogen balance was -82 +/- 51 mg.kg-1/d in the parenteral nutrition group vs +70 +/- 7 mg.kg-1/d in the enteral nutrition group (P < 0.05). The results showed that balanced enteral nutrition had less weight loss and better cumulative nitrogen balance than standard parenteral nutrition in this protocol. More patients study will be needed.

Propagation of apertured Bessel beams

The propagation features of several apertured Bessel beams are numerically calculated. The calculations show that the relations of axial intensity versus propagation distance are similar to the radial distribution of the aperture functions, which may be helpful in choosing the proper aperture functions in experiments.

[A comparative study of fat emulsions clearance test using long chain triglycerides and medium chain triglycerides in volunteers]

Intravenous fat emulsions clearance test using long chain triglycerides (LCT) and medium chain triglycerides (50% MCT/LCT) were studied in ten healthy chinese volunteers. In the morning (8:00 AM) the lipid was infused continuously for 5 hours at rate of 0.17g.kg-1/h. There was an interval of two weeks between LCT and MCT/LCT. The peak concentration of serum triglyceride was smaller in MCT group. The area under concentration curve had significant difference between LCT and MCT groups (6108 +/- 461 vs 4495 +/- 362, P < 0.05). The serum free fatty acid was 628 +/- 42 in LCT and 1049 +/- 1 in MCT respectively in 5 hour (P < 0.001). The concentrations of very low-density lipoprotein (VLDL) in serum were increased in volunteers receiving LCT and MCT, but those of LDL and HDL were decreased. The blood sugar and cholesterol had no significant difference after lipids infusions. The study demonstrated that medium chain triglycerides was faster to be cleared than long chain triglycerides.

[Lymphatic metastasis in central direction and bowel axial direction in colonic cancers]

485 lymph nodes were founded by palpation in 44 R3 resected specimens of colonic cancers. In the bowel axial direction, the rate of lymphatic metastasis was 6.8%, which accound for 9.6% of the positive lymph node metastasis. All these positive nodes were limited from 10 cm proximal to 5 cm distal to the tumor. In the central direction, the rate of mesenteric lymphatic metastasis was 20.4%, and the rate of lymphatic metastasis at the root of mesentery was 4.5%, which accounted for 38.1% of the positive lymph node metastasis. Compared to the bowel axial direction, mesenteric lymphatic metastasis in the central direction was more common and should be carefully disseted during radical operation.

Absorption, tissue distribution and in vivo stability in rats of a hybrid antisense oligonucleotide following oral administration

In vivo stability and oral bioavailability of an oligodeoxynucleotide phosphorothioate containing segments of 2'-O-methyloligoribonucleotide phosphorothioates at both the 3'- and 5'-ends (hybrid oligonucleotide) were studied. A 25-mer 35S-labeled hybrid oligonucleotide was administered to rats by gavage at a dose of 50 mg/kg body weight. HPLC analysis revealed that this hybrid oligonucleotide was stable in the gastrointestinal tract for up to 6 hr following oral administration. Radioactivity associated with the hybrid oligonucleotide was detectable in portal venous plasma, systemic plasma, various tissues, and urine. Intact hybrid oligonucleotide was detected, by HPLC analysis, in portal venous plasma, systemic plasma, and various tissues. The majority of the radioactivity in urine was associated with degradative products with lower molecular weights, but the intact form was also detected. In summary, the hybrid oligonucleotide was absorbed intact through the gastrointestinal tract, indicating the possibility of oral administration of oligonucleotides, a finding that may be important in the development of antisense oligonucleotides as therapeutic agents.