The benefit of prothrombin complex concentrate in decreasing neurological deterioration in patients with warfarin-associated intracerebral haemorrhage.

OBJECTIVE: To compare the outcomes of patients with warfarin-associated intracerebral haemorrhage given different treatments to reverse the effect of anticoagulation. DESIGN: Historical cohort study. SETTING: A regional hospital in Hong Kong. PATIENTS: Patients on warfarin who developed intracerebral haemorrhage. INTERVENTIONS: Prothrombin complex concentrate versus fresh frozen plasma treatment. MAIN OUTCOME MEASURES: The primary outcome measures included the international normalised ratio before and after prothrombin complex concentrate treatment and the neurological deterioration in patients with Glasgow Coma Scale score of more than 8/not intubated/not planned for immediate surgery (target group). Secondary outcome measures were haematoma expansion, 7-day and 30-day mortality rates, and 3-month functional outcome. Safety outcome was the occurrence of a thrombotic event after prothrombin complex concentrate treatment within the index admission. RESULTS: Among 33 patients with clearly documented time of infusion of prothrombin complex concentrate, and whose international normalised ratio was checked before and after prothrombin complex concentrate treatment, the mean international normalised ratio was reduced from 2.81 to 1.21 within 24 hours. Within the target group of patients, there was a significantly lower rate of neurological deterioration in the prothrombin complex concentrate group (17.4% of 23 patients) versus fresh frozen plasma group (45.5% of 33 patients) [P=0.027]. In terms of the 7-day mortality, 30-day mortality, and 3-month functional outcome, prothrombin complex concentrate-treated group showed a favourable trend although the difference did not reach a statistical significance. No patient developed thrombotic complications after prothrombin complex concentrate treatment. CONCLUSIONS: Prothrombin complex concentrates can reverse the warfarin effect of prolonged international normalised ratio in a timely manner. It might better improve the outcome of warfarin-associated intracerebral haemorrhage compared with fresh frozen plasma treatment by reduction in neurological deterioration.

Electronic transitions of palladium dimer.

The laser induced fluorescence spectrum of palladium dimer (Pd2) in the visible region between 480 and 700 nm has been observed and analyzed. The gas-phase Pd2 molecule was produced by laser ablation of palladium metal rod. Eleven vibrational bands were observed and assigned to the [17.1](3)Πg-X(3)Σu(+) transition system. The bond length (ro) and vibrational frequency (ΔG1∕2) of the ground X(3)Σu(+) state were determined to be 2.47(4) Å and 211.4(5) cm(-1), respectively. A molecular orbital energy level diagram was used to understand the observed ground and excited electronic states. This is the first gas-phase experimental investigation of the electronic transitions of Pd2.

Electronic transitions of ruthenium monoxide.

The electronic transition spectrum of ruthenium monoxide (RuO) molecule in the spectral region between 545 nm to 640 nm has been recorded and analyzed using laser ablation/reaction free-jet expansion and laser induced fluorescence spectroscopy. The RuO molecule was produced by reacting laser-ablated ruthenium atoms with N2O seeded in argon. Nine vibrational bands were recorded, and they are identified to belong to four electronic transition systems, namely, the [18.1]Ω = 4-X(5)Δ4, [16.0]Ω = 5-X(5)Δ4, [18.1]Ω = 3-X(5)Δ3, and [15.8]Ω = 4-X(5)Δ3 systems. RuO was determined to have a X(5)Δ4 ground state. A least-squares fit of the measured rotational lines yielded molecular constants for the ground and the low-lying electronic states. A molecular orbital energy level diagram has been used to help with the assignment of the observed electronic states.

Electronic transition of palladium monoboride.

The laser-induced fluorescence spectrum of palladium monoboride (PdB) in the visible region between 465 and 520 nm has been observed and analyzed. Gas-phase PdB molecules were produced by the reaction of diborane (B(2)H(6)) seeded in argon with laser ablated palladium atoms. Thirteen vibrational bands have been recorded, which included transitions of both Pd(10)B and Pd(11)B isotopic species. These bands belong to the [19.7](2)Σ(+)-X(2)Σ(+) system, with ground X(2)Σ(+) state bond length, r(o), determined to be 1.7278 Å. A molecular orbital energy level diagram was used to understand the observed ground and excited electronic states. This work represents the first experimental investigation of the electronic spectroscopy of the PdB molecule.

Electronic transitions of platinum monoboride.

The electronic transition spectrum of platinum monoboride (PtB) radical has been observed for the first time. Using laser vaporization∕reaction free jet expansion and laser induced fluorescence spectroscopy, the optical spectrum of PtB in the visible region between 455 and 520 nm has been studied. Gas-phase PtB molecule was produced by the reaction of diborane (B(2)H(6)) seeded in argon and laser ablated platinum atom. Seven vibrational bands of the Pt(11)B radical have been recorded and analyzed. The observation of Pt isotopic molecules and the Pt(10)B isotope confirmed the carrier of the bands. Two different transition systems, namely: the [20.2]3/2-X(2)Σ(+) and the [21.2]1/2-X(2)Σ(+) systems were identified. PtB was determined to have an X(2)Σ(+) ground state and the bond length, r(e), was determined to be 1.741 Å.

Electronic transitions of iridium monoxide: ground and low-lying electronic states.

The electronic transition spectrum of IrO in the spectral region between 448 and 650 nm has been recorded and analyzed using laser vaporization/reaction free jet expansion and laser induced fluorescence spectroscopy. The IrO molecule was produced by reacting laser-ablated iridium atoms with N(2)O seeded in argon. Five electronic transition systems, namely, the [17.6]2.5 - X(2)Δ(5/2), [17.8]2.5 - X(2)Δ(5/2), [21.5]2.5 - X(2)Δ(5/2), [22.0]2.5 - X(2)Δ(5/2), and [21.9]3.5 - Ω = 3.5 systems were identified. Transition lines of both the (191)IrO and (193)IrO isotopes were observed and analyzed. IrO was determined to have a X(2)Δ(5/2) ground state. A least squares fit of the measured rotational lines yielded molecular constants for the ground and low-lying electronic states. A molecular orbital energy level diagram has been used to help with the assignment of the observed electronic states.

Electronic transitions of cobalt monoboride.

Electronic transition spectrum of cobalt monoboride (CoB) in the visible region between 495 and 560 nm has been observed and analyzed using laser-induced fluorescence spectroscopy. CoB molecule was produced by the reaction of laser-ablated cobalt atom and diborane (B(2)H(6)) seeded in argon. Fifteen vibrational bands with resolved rotational structure have been recorded, which included transitions of both Co(10)B and Co(11)B isotopic species. Our analysis showed that the observed transition bands are ΔΩ = 0 transitions with Ω" = 2 and Ω" = 3 lower states. Four transition systems have been assigned, namely, the [18.1](3)Π(2)-X(3)Δ(2), the [18.3](3)Φ(3)-X(3)Δ(3), the [18.6]3- X(3)Δ(3), and the [19.0]2-X(3)Δ(2) systems. The bond length, r(o), of the X(3)Δ(3) state of CoB is determined to be 1.705 Å. The observed rotational lines showed unresolved hyperfine structure arising from the nuclei, which conforms to the Hund's case (a(ß)) coupling scheme. This work represents the first experimental investigation of the CoB spectrum.

Hyperammonaemic encephalopathy in an adult patient with citrin deficiency associated with a novel mutation.

We report on an adult patient with citrin deficiency in Hong Kong, in whom a novel mutation was identified. The patient presented with recurrent hyperammonaemic encephalopathy due to impairment of the liver urea cycle enzyme argininosuccinate synthetase. This autosomal recessive condition is also characterised by interesting food preferences, notably aversion to carbohydrates and craving for protein-rich and/or lipid-rich foods, as well as neuropsychiatric symptoms. Plasma amino acid analysis is very useful in revealing urea cycle disorders, and mutational analysis of the SLC25A13 gene can confirm the diagnosis.

Prevalence and significance of white-coat hypertension and masked hypertension in type 2 diabetics.

OBJECTIVES: To explore the prevalence of various categories of hypertension in diabetic patients, and assess any corresponding associations with end-organ complications. DESIGN: Cross-sectional study. SETTING: Tertiary centre of a regional hospital in Hong Kong. PATIENTS: All ambulatory type 2 diabetic patients attending our clinics from January 2002 to November 2004 were invited to participate in the protocol. RESULTS: A total of 133 diabetic patients were included; 82 had normal clinic blood pressures, 15 (18%) of whom had masked hypertension, the remaining 67 (82%) had 'normotension'. The remaining 51 patients had high clinic blood pressures, of whom 28 (55%) had white-coat hypertension and 23 (45%) had sustained hypertension. Urinary albumin excretion rate was higher in patients with masked hypertension (10 mg/day; range, 7-580 mg/day) and sustained hypertension (7 mg/day; 7-3360 mg/day) in comparison to those with white-coat hypertension (7 mg/day; 7-109 mg/day) or 'normotension' (7 mg/day; 7-181 mg/day) [P<0.01]. Likewise, the prevalence of albuminuria was significantly higher in patients with masked hypertension (40%) and sustained hypertension (26%) than in those with 'normotension' (6%) and white-coat hypertension (11%) [P<0.01]. The prevalence of left ventricular hypertrophy was significantly higher in subjects with masked hypertension (38%) and sustained hypertension (26%) compared to patients with 'normotension' (8%) or white-coat hypertension (11%) [P<0.01]. Left ventricular diastolic dysfunction was more prevalent in patients with masked hypertension (46%), sustained hypertension (48%), and white-coat hypertension (43%) in comparison to subjects with 'normotension' (18%) [P=0.01]. CONCLUSION: Masked hypertension is associated with a higher prevalence of albuminuria, left ventricular diastolic dysfunction, and hypertrophy. White-coat hypertension carries a more benign prognosis than sustained hypertension and masked hypertension. Our cross-sectional study supports the recommendation to performing ambulatory blood pressure measurements in type 2 diabetic patients.

In vivo model to determine fetal-cell enrichment efficiency of novel noninvasive prenatal diagnosis methods.

OBJECTIVE: To develop an in vivo model to determine fetal-cell enrichment efficiency of novel noninvasive prenatal diagnosis methods. METHODS: Efficiency of our three-step enrichment protocol was determined in vitro before fetal nucleated red blood cells (FNRBCs) were enriched from first-trimester maternal blood samples collected from the same patients pre- and postsurgical termination of pregnancy (TOP) (n = 10). FNRBCs enriched were identified using embryonic epsilon-globin immunocytochemistry and chromosomal fluorescence in situ hybridization. RESULTS: We recovered 37% of spiked FNRBCs (95% confidence interval (CI) 28.5-45.6; n = 8) in in vitro experiments. We show a consistent threefold increase in the number of epsilon + FNRBCs in maternal blood obtained immediately post-TOP (p = 0.005). A mathematical relationship was derived: observed number of pretermination primitive FNRBCs = 0.6 + 0.31 (coefficient between pretermination/post-termination primitive FNRBCs, 95% CI 0.12-0.49; p = 0.005) x observed number of post-termination primitive FNRBCs (R2 = 0.65). CONCLUSION: Our data demonstrate that maternal blood obtained immediately post-TOP would be a good in vivo model to determine the enrichment efficiency of novel protocols and methods for noninvasive prenatal diagnosis.

Needlestick injury among medical personnel in Accident and Emergency Department of two teaching hospitals.

Needlestick injury has been recognized as one of the occupational hazards which results in transmission of bloodborne pathogens. A cross-sectional study was carried out among 136 health care workers in the Accident and Emergency Department of two teaching hospitals from August to November 2003 to determine the prevalence of cases and episodes of needlestick injury. In addition, this study also assessed the level of knowledge of blood-borne diseases and Universal Precautions, risk perception on the practice of Universal Precautions and to find out factors contributing to needlestick injury. Prevalence of needlestick injury among the health care workers in the two hospitals were found to be 31.6% (N = 43) and 52.9% (N = 87) respectively. Among different job categories, medical assistants appeared to face the highest risk of needlestick injury. Factors associated with needlestick injury included shorter tenure in one's job (p < 0.05). Findings of this study support the hypothesis that health care workers are at risk of needlestick injury while performing procedures on patients. Therefore, comprehensive infection control strategies should be applied to effectively reduce the risk of needlestick injury.

Use of lithium in the treatment of thyrotoxicosis.

OBJECTIVES: To evaluate the efficacy and safety of lithium in the treatment of thyrotoxicosis, and to study the dose and serum levels at which therapeutic response occurs. DESIGN: Retrospective study. SETTING: Thyroid clinic of a regional hospital in Hong Kong. PATIENTS: Thirteen patients with thyrotoxicosis pending therapy with radioiodine or surgery, in whom thionamides were contra-indicated due to adverse reactions or failure of treatment. MAIN OUTCOME MEASURES: Free thyroxine levels, time to euthyroidism, and side-effects of lithium. RESULTS: A satisfactory response, defined as a fall by 40% or more in free thyroxine levels and clinical improvement, was achieved in eight patients within 1 to 2 weeks of lithium therapy. In four others, response occurred in 3 to 5 weeks. Response was slow and inadequate in one patient due to 'escape'. The median dosage of lithium was 750 mg daily, with a range of 500 to 1500 mg daily. The median serum lithium level was 0.63 mmol/L. Lithium toxicity was observed in one patient. CONCLUSIONS: A relatively low dose of lithium offers a safe and effective alternative means of controlling thyrotoxicosis in patients who cannot tolerate or do not respond to thionamides.

Combined orbital irradiation and systemic steroids compared with systemic steroids alone in the management of moderate-to-severe Graves' ophthalmopathy: a preliminary study.

OBJECTIVE: To assess the efficacy and safety of combined orbital irradiation and systemic steroids in the management of moderate-to-severe Graves' ophthalmopathy. DESIGN: Single-blind randomised prospective study. SETTING: Regional hospital, Hong Kong. PATIENTS: Sixteen patients with active moderate-to-severe Graves' ophthalmopathy who were randomly assigned to steroid therapy (ST group) or combination therapy of orbital irradiation and systemic steroids (SRT group) between June 2000 and June 2003. MAIN OUTCOME MEASURES: NOSPECS scoring system, total eye score, subjective eye score, and extra-ocular muscle thickness as determined by either computed tomographic or magnetic resonance imaging scans. RESULTS: The study was completed by 15 of 16 patients. Both groups experienced improvement in total eye score, soft tissue swelling, ocular motility, visual acuity, and subjective eye score at 52-week follow-up. Total eye score improved earlier in the SRT group, achieving statistical significance (P<0.05) at as early as 4 weeks of follow-up. Improvement in ocular parameters was greater and led to a significantly greater reduction in total eye score than in the ST group at weeks 16, 24, and 52. Maximum extra-ocular muscle thickness was significantly reduced in the SRT group only. No change was observed in proptosis in either group. No serious adverse effect was observed with the addition of orbital irradiation to steroid therapy. CONCLUSION: A combination of orbital irradiation and systemic steroids is well tolerated and more effective than steroids alone in the treatment of active moderate-to-severe Graves' ophthalmopathy. It achieves greater and more rapid improvement in soft tissue swelling, ocular motility, and visual acuity.

Does lead damage motor neurons?

It has been suggested that lead (Pb) may damage motor neurons selectively after retrograde axonal transport from the neuromuscular junction. This has reinforced suspicions that Pb could be a cause of some sporadic motor neuron diseases. However, the long-term effect of Pb on spinal motor neurons is not known. To investigate this, we injected mice in the right hindlimb with 0.1 ml of 2.5% Pb nitrate. Nine months later we measured the sizes and counted the numbers of motor neuron cell bodies in the anterior horns of the L4 spinal cord. There was no significant difference in sizes or numbers of motor neuron cell bodies between the left and right sides of the spinal cord in either group or between groups. These data do not therefore support the hypothesis that Pb transported from muscle damages spinal motor neurons.

Sciatic nerve injury in the adult rat: comparison of effects on oligosaccharide, CGRP and GAP43 immunoreactivity in primary afferents following two types of trauma.

Using immunocytochemical and morphometric techniques, the localisation of three neuronal oligosaccharide antigens (two lactoseries and one globoseries oligosaccharide) were studied in the spinal cord and dorsal root ganglia of adult rats following unilateral crushing or transection of the sciatic nerve. The expression of CGRP and GAP43 was also studied for comparison. We found that following transection of the nerve the expression of lactoseries oligosaccharides and CGRP was permanently depressed, whilst that of the globoseries antigen (SSEA4) was unaffected. However following crush trauma and subsequent regeneration after 2 months, only the expression of one lactoseries antigen, LA4 remained significantly depressed. Our results suggest that different subsets of sensory neurons vary in the rate of reaction to injury and that one subset of neurons expressing a lactoseries oligosaccharide antigen is particularly susceptible to axotomy-induced changes. Furthermore neurons expressing the globoseries oligosaccharide antigen SSEA4 appear to be relatively unaffected by peripheral axotomy.

Spinal cord uptake of lead injected into muscle.

It has been hypothesised that some motor neuron diseases may result from lead (Pb) being retrogradely transported in axons from muscle to spinal cord. To test this hypothesis, we injected mice in the right hindlimb with 0.1 ml of 0.25% or 2.5% Pb. In some animals the sciatic nerve was cut before injection. Pb levels were measured in the lumbar and thoracic spinal cord and the kidney with atomic absorption spectrophotometry (AAS). Four weeks after injection, Pb was found in the spinal cord on AAS, with higher levels in the lumbar than the thoracic cord only in the high-Pb group. Sciatic nerve cut did not inhibit the passage of Pb to the cord. The results suggest that most Pb injected into muscle reaches the spinal cord via the blood or damaged axons, rather than via intact axons. These data do not support the hypothesis of Pb-induced motor neuron disease via retrograde axonal transport from muscle.