Pregnancy complicated by malaria, precipitate labor and uterine rupture.

A case of Plasmodium falciparum malaria is reported in a 25-year-old pregnant woman with a history of three previous cesarean sections. She developed premature precipitate labor which was complicated by stillbirth, uterine rupture, bladder and vaginal tears necessitating hysterectomy.     

Medullary control of the pontine swallowing neurones in sheep

Summary The origin of the inputs from the medullary swallowing centre (dorsal region including the nucleus of the solitary tract, or ventral region corresponding to the reticular formation surrounding the nucleus ambigous) to the pontine swallowing neurones (PSNs) was studied in sheep anaesthetized with halothane.Out of 101 PSNs located in the posterior part of the trigeminal (Vth) motor nucleus, 46 were activated by stimulating either the dorsal (21 neurones) or the ventral (25 neurones) region of the ipsilateral medullary swallowing centre, 3–4 mm rostral from the obex. Thirty-one neurones out of the 46 were identified as a motoneurones supplying swallowing muscles (mylohyoïd, anterior body of digastric and medial pterygoïd). Their average activation latency through stimulation of the dorsal medullary region was about 1 ms longer than through stimulation of the ventral region (3.63 ms±0.81 versus 2.72 ms±0.32).To determine the origin of the medullary input to the PSNs, we tried to activate the medullary swallowing neurones (MSNs) antidromically through stimulating the posterior part of the Vth motor nucleus, which contains the swallowing motoneurones. Seventy-three MSNs were tested (25 located in the dorsal and 48 in the ventral region). None of the dorsal neurones tested could be antidromically activated by pontine stimulation: 15 ventral neurones showed a clear antidromic response (collision test) with an average latency of 2.5 ms±0.73. These neurones, which send their axons into the pons, were all located in the reticular formation, above the nucleus ambiguus, 3–4 mm rostral from the obex.These results suggest that MSNs in the ventral reticular formation connect the medullary swallowing centre to the Vth motor nucleus. They also suggest that during swallowing, inputs originating from the dorsal region of the medullary centre (interneurones programming the motor sequence) are relayed in the ventral region (reticular formation adjacent to the nucleus ambiguus) before reaching the PSNs.This work was supported, in part, by grants from CNRS (LA 205), INRA and M.R.I. (82 E 0685)     

Protocols for the dosimetry of high-energy photon and electron beams: a comparison of the IAEA TRS-398 and previous international codes of practice. International Atomic Energy Agency

A new international Code of Practice for radiotherapy dosimetry co-sponsored by several international organizations has been published by the IAEA, TRS-398. It is based on standards of absorbed dose to water, whereas previous protocols (TRS-381 and TRS-277) were based on air kerma standards. To estimate the changes in beam calibration caused by the introduction of TRS-398, a detailed experimental comparison of the dose determination in reference conditions in high-energy photon and electron beams has been made using the different IAEA protocols. A summary of the formulation and reference conditions in the various Codes of Practice, as well as of their basic data, is presented first. Accurate measurements have been made in 25 photon and electron beams from 10 clinical accelerators using 12 different cylindrical and plane-parallel chambers, and dose ratios under different conditions of TRS-398 to the other protocols determined. A strict step-by-step checklist was followed by the two participating clinical institutions to ascertain that the resulting calculations agreed within tenths of a per cent. The maximum differences found between TRS-398 and the previous Codes of Practice TRS-277 (2nd edn) and TRS-381 are of the order of 1.5-2.0%. TRS-398 yields absorbed doses larger than the previous protocols, around 1.0% for photons (TRS-277) and for electrons (TRS-381 and TRS-277) when plane-parallel chambers are cross-calibrated. For the Markus chamber, results show a very large variation, although a fortuitous cancellation of the old stopping powers with the ND,w/NK ratios makes the overall discrepancy between TRS-398 and TRS-277 in this case smaller than for well-guarded plane-parallel chambers. Chambers of the Roos-type with a 60Co ND,w calibration yield the maximum discrepancy in absorbed dose, which varies between 1.0% and 1.5% for TRS-381 and between 1.5% and 2.0% for TRS-277. Photon beam calibrations using directly measured or calculated TPR20,10 from a percentage dose data at SSD = 100 cm were found to be indistinguishable. Considering that approximately 0.8% of the differences between TRS-398 and the NK-based protocols are caused by the change to the new type of standards, the remaining difference in absolute dose is due either to a close similarity in basic data or to a fortuitous cancellation of the discrepancies in data and type of chamber calibration. It is emphasized that the NK-ND,air and ND,w formalisms have very similar uncertainty when the same criteria are used for both procedures. Arguments are provided in support of the recommendation for a change in reference dosimetry based on standards of absorbed dose to water.     

Risk factors for retinopathy in diabetes mellitus in Kelantan, Malaysia

Few attempts have been made to determine the risk factors for diabetic retinopathy which is a major cause of visual impairment and blindness. One hundred and forty patients of diabetes mellitus were studied to determine the prevalence and types of retinopathy, and its relation to various risk factors. Nearly half (48.6%) of the patients suffered from retinopathy. The significant associated risk factors were long duration of diabetes, proteinuria and elevated serum creatinine level. However, there was no significant association between the prevalence of retinopathy and high levels of serum cholesterol, C-peptide levels, associated hypertension, and glycaemic control of diabetes mellitus. An effective screening programme for detection of retinopathy in the patients of diabetes as a regular practice is encouraged.     

Vascular complications of infective endocarditis: a retrospective analysis of 18 cases

OBJECTIVES: Among 82 patients hospitalized for infective endocarditis between June 1995 and June 2001 at the cardiology B unit of the Rabat University Hospital Morocco, 18 (22%) had one or more vascular complications. We present here a retrospective analysis. PATIENTS AND METHODS: The cohort included 12 men and 6 women, mean age 22 years. Infective endocarditis had grafted on a pre-existing cardiopathy among 17 patients: rheumatic heart disease (n=14), mechanical prosthetic valve (n=2), congenital heart disease (n=1). RESULTS: For 12 patients, vascular disease was the only complication, 1 had two complications and 4 three complications. This gave 26 lesions: 11 neurological complications, 10 arterial diseases involving the limbs including 5 mycotic aneurysms, 2 acute myocardial infarcts, 2 splenic infarcts, and 1 recurrent septic pulmonary embolism. Vascular disease was the inaugural manifestation in 9 patients and 54% of the complications occurred before the end of the second week of antibiotic treatment. Blood cultures were positive in 7 patients (40%). Oral streptococcus was isolated in 5 cases, Gram-negative bacillus in 1 case and Staphylococcus aureus in 1. Echography revealed valvular vegetations in the 16 cases of infective endocarditis on native valves: mitral (n=9), aortic (n=5), mitroaortic (n=1), tricuspid (n=1). Short term outcome was marked by 4 deaths including 3 directly related to the vascular complication. DISCUSSION: We emphasize the variable and diverse features of vascular complications of infective endocarditis. Prevention and early diagnosis are essential to institute optimal management of infective endocarditis.     

Magnetic and Tunable Sound Absorption Properties of an In-Situ Prepared Magnetorheological Foam

Conventional polyurethane foam has non-tunable sound absorption properties. Here, a magneto-induced foam, called magnetorheological (MR) foam, was fabricated with the feature of being able to tune sound absorption properties, primarily from the middle- to higher-frequency ranges. Three different samples of MR foams were fabricated in situ by varying the concentration of Carbonyl Iron Particles (CIPs) (0, 35, and 75 wt.%). The magnetization properties and tunable sound absorption characteristics were evaluated. From the magnetic saturation properties, the results showed very narrow and small coercivity of hysteresis loops relative to the soft magnetic properties of the CIPs. MR foam with 75 wt.% CIPs showed a higher magnetic saturation at 91.350 emu/g compared to MR foam with 35 wt.% CIPs at 63.896 emu/g. For tunable sound absorption testing, the effect of ‘shifting’ to higher frequency was also observed when the magnetic field was applied, which was ~10 Hz for MR foam with 35 wt.% CIPs and ~130 Hz for MR foam with 75 wt.% CIPs. As the latest evolution of semi-active noise control materials, the results from this study are valuable guidance for the advancement of MR-based devices.