La détection de la maladie d'Alzheimer par le médecin généraliste : résultats d'une enquête préliminaire auprès des médecins du réseau Sentinelles

CONTEXT

The availability of cholinesterase inhibitors has reinforced the need for early detection of Alzheimer's disease in which the general practitioner plays a key role. This study seeks to appraise the diagnostic procedures of Alzheimer's disease in general medicine.

METHOD

A postal survey of 1176 general practitioners belonging to the French Sentinelles network.

RESULTS

Response rate: 43%. The surveyed doctors have seen 1.5 new cases in 2002, and were in charge of the follow-up of four patients. Reasons leading to consultation were: memory impairment (84%), memory impairment together with decline in daily functioning and disorientation (42%). Seventy-six per cent of the Sentinelles used the MMSE, 91% referred the patient to a specialist. Fifty-four per cent announced the diagnosis to the patient; 94% to the family. Twenty-six per cent of the surveyed doctors systematically used the DSM-IV criteria and 77% considered early diagnosis valuable.

CONCLUSION

The results of this survey show that Alzheimer's disease is still under-diagnosed in general medicine in spite of the general practitioner's favourable opinion as to early diagnosis of the disease. Compared to his European colleagues, French general practitioner's attitude is characterized by frequent referral to a specialist service, follow-up of diagnostic criteria and frequency of disclosure of diagnosis to the family.

Stereoscopic vision provides a significant advantage for precision robotic laparoscopy

BACKGROUND

Current surgical robots provide no sense of touch and rely solely upon vision. This study evaluated the effect of new stereoscopic technology on the performance of robotic precision laparoscopy.

METHODS

Eight experienced laparoscopists with no experience in robotics performed five tasks of increasing complexity using a laparoscopic robot. The tasks were as follows: rope pass, paper cut, needle capping, knot tying and needle threading. Each test was performed ten times under both stereoscopic and monoscopic conditions. Performance times and errors were recorded.

RESULTS

Mean(s.e.m.) final performance times were calculated from the final five trial times for each test, and were as follows for monoscopic and stereoscopic conditions respectively: rope pass 112.8(4.2) and 97.0(3.7) s (P = 0.013), paper cut 117.1(6.0) and 98.4(9.8) s (P = 0.020), needle capping 144.5(12.7) and 99.7(6.8) s (P = 0.008), knot tying 138.7(14.3) and 70.3(6.0) s (P = 0.002), and needle threading 210.8(28.2) and 92.3(4.1) s (P = 0.002). The mean(s.e.m.) number of errors per candidate was 60.6(7.8) and 20.8(3.9) under monoscopic and stereoscopic conditions respectively (P = 0.004).

CONCLUSION

Stereoscopic vision provided a significant advantage during robotic laparoscopy in situations that required a precise understanding of structural orientation.

Organs transplanted from intoxicated donors

PURPOSE

The purpose of our study was to evaluate short- and long-term results of transplants from cadaver donors who have died of poisoning by various substances.

MATERIALS AND METHODS

The actuarial survival rate of organs from intoxicated donors was calculated using the Kaplan-Meier method.

RESULTS

Among the 507 donors between January 1998 and December 2002, 5 (0.98%) had a cause of brain death of poisoning, namely, organo-phosphates (n = 2), methanol (n = 1), cyanide (n = 1) and acetylsalicilic acid(n = 1), from whom were procured 10 kidneys, 1 liver, 2 corneas, and 1 set of bones. The follow up for patients receiving solid organs was 15.2 months (range, 0-48 months). At 3 months, 90% of kidneys had normal function. No delayed graft function rejection episodes or major complications were reported in any recipient. None showed evidence of acute or chronic poisoning. Two died, 1 early mortality was due to anesthetic complications and the other at 17 months to an unknown cause. Actuarial kidney survival rates were 90% and 80% at 12 and 24 months, respectively. The liver recipient was well at the end of follow up.

CONCLUSION

Using organs of poisoned donors is feasible with comparable graft survival rates to other recipient.

Lactation under induced five-month delay reproduction in Iberian red deer (Cervus elaphus hispanicus)

In Iberian deer, calf birth date affects both milk production and composition, as well as the weight change of hind during lactation and calf growth. This study examines a five-month induced delay in calving (autumn group) in a group of 19 Iberian hinds compared to a group of 13 standard calving hinds (spring group). Fertility in the autumn group was half that of the spring one. From the former, a further two calves out of six died before or soon after birth. Successfully lactating hinds showed a greater concentration in protein, fat and lactose (P < 0.001), but did not differ from spring group in total milk yield, calf gain or weight change of hinds during lactation. However, after correcting for the greater calf or hind body weight at calving of the autumn group, this group showed lower values for these variables than the spring group. Results show that at least in Iberian deer, counter-season reproduction is possible, and that the effects on lactation variables are similar to those of a natural delay in calving.

Performance of the acetic acid test when used in field conditions as a screening test for cervical cancer

OBJECTIVE

To assess if visual inspection with acetic acid (VIA) is a useful alternative screening test for cervical cancer, when used in a resource-poor setting with an existing cytology-based screening programme.

METHODS

Women living in Rivas district (Nicaragua), who attended the programme, were concurrently screened with VIA and Papanicolau (PAP) smear. Screening was performed by health providers who had received training in VIA and a refresher course in cytology. Women testing positive for either of the results were referred for colposcopy and biopsy when indicated. The performance of VIA was compared with PAP smear, calculating the relative true and false positive rate (RELTPR and RELFPR) and for a high threshold on biopsy (cervical intraepithelial neoplasia grade 2 or a higher grade). We determined the trade-off between both tests by calculating the ratio of extra false positives detected through extra true positives (EFP:ETP ratio).

RESULTS

A total of 1076 patients were screened. Nearly 33% had a positive screening test. On biopsy, 7.6% had a low-grade intraepithelial lesion, 4.5% a high-grade intraepithelial lesion (HSIL) and 0.5% invasive cancer. The RELTPR (VIA to PAP) was 1.96, the RELFPR 5.02 and the EFP:ETP ratio 8.04. VIA detected twice as much HSIL and invasive cancers as the PAP smear. Yet, for every extra diagnosis, eight extra false positives had to be examined at the referral level.

CONCLUSIONS

The VIA spectacularly increases the number of HSIL and invasive cancers detected. The high FPR is a concern for the organization of the referral level. There is a need to establish uniform criteria on test positivity and to further improve the performance in field conditions.

Stage determination and therapeutic decision in human African trypanosomiasis: value of polymerase chain reaction and immunoglobulin M quantification on the cerebrospinal fluid of sleeping sickness patients in Côte d'Ivoire

In human African trypanosomiasis (HAT), two disease stages are defined: the first, or haemo-lymphatic stage, and the second, or meningo-encephalitic stage. Stage determination forms the basis of therapeutic decision and is of prime importance, as the drug used to cure second-stage patients has considerable side-effects. However, the tests currently used for stage determination have low sensitivity or specificity. Two new tests for stage determination in the cerebrospinal fluid (CSF) were evaluated on 73 patients diagnosed with HAT in Côte d'Ivoire. The polymerase chain reaction (PCR) detecting trypanosome DNA (PCR/CSF) is an indirect test for trypanosome detection whereas the latex agglutination test detecting immunoglobulin M (LATEX/IgM) is an indicator for neuro-inflammation. Both tests were compared with classically used tests, double centrifugation and white blood cell count of the CSF. PCR/CSF appeared to be the most sensitive test (96%), and may be of use to improve stage determination. However, its value for therapeutic decision appears limited, as patients whose CSF was positive with PCR were successfully treated with pentamidine. This result confirms those of previous works that showed that some patients with trypanosomes in the CSF could be treated successfully with pentamidine. LATEX/IgM, which depending on the cut-off, showed lower sensitivity of 76% and 88%, but higher specificity of 83% and 71% for LATEX/IgM 16 and LATEX/IgM 8 respectively, appears more appropriate for therapeutic decision making.

Enzyme replacement therapy in mucopolysaccharidosis type II (Hunter syndrome): a preliminary report

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is an X-linked disease caused by a deficiency of the enzyme iduronate-2-sulphatase (IDS), which results in the lysosomal accumulation of glycosaminoglycans (GAG). This paper describes a knockout mouse model of MPS II which has been used to assess the effect of enzyme replacement therapy. Therapy with IDS results in a marked decrease in urinary GAGs, as well as reduced GAG accumulation in several tissues. These studies have been used to support the first clinical trial of recombinant IDS in patients with Hunter syndrome.

Stromal tumor in a perforated Meckel's diverticulum: a case report

Stromal tumors are rare neoplasms of the small bowel that locate in Meckel's diverticulum with high preference. Perforation of those tumors is very uncommon. There are 96 cases reported in current literature, including only 6 perforations. The diagnosis of that kind of tumor is very difficult because of lack of pathognomonic signs and symptoms. The clinical presentation include abdominal pain, intestinal bleeding, abdominal mass, intestinal obstruction and less commonly, acute perforation. We report the case of a 61-years old patient with a poorly differentiated stromal tumor in a perforated Meckel's diverticulum. The difficulty of identifying a stromal tumor preoperatively and the therapeutic options are emphasised. It is suggested that an aggressive attitude should be taken in the preoperative management of any patient over 50 years of age who presents with melena and abdominal pain.

Stress reactivity of the brain noradrenergic system in three rat strains differing in their neuroendocrine and behavioral responses to stress: implications for susceptibility to stress-related neuropsychiatric disorders

The brain noradrenergic system is activated by stress, modulating the activity of forebrain regions involved in behavioral and neuroendocrine responses to stress. In this study, we characterized brain noradrenergic reactivity to acute immobilization stress in three rat strains that differ in their neuroendocrine stress response: the inbred Lewis (Lew) and Wistar-Kyoto (WKY) rats, and outbred Sprague-Dawley (SD) rats. Noradrenergic reactivity was assessed by measuring tyrosine hydroxylase mRNA expression in locus coeruleus, and norepinephrine release in the lateral bed nucleus of the stria terminalis. Behavioral measures of arousal and acute stress responsivity included locomotion in a novel environment, fear-potentiated startle, and stress-induced reductions in social interaction and open-arm exploration on the elevated-plus maze. Neuroendocrine responses were assessed by plasma adrenocorticotropic hormone. Compared to SD, adrenocorticotropic hormone responses of Lew rats were blunted, whereas those of WKY were enhanced. The behavioral effects of stress were similar in Lew and SD rats, despite baseline differences. Lew had similar elevations of tyrosine hydroxylase mRNA, and initially greater norepinephrine release in the lateral bed nucleus of the stria terminalis during stress, although both noradrenergic responses returned toward baseline more rapidly than in SD rats. WKY rats showed depressed baseline startle and lower baseline exploratory and social behavior than SD. However, unlike the Lew or SD rats, WKY exhibited a lack both of fear potentiation of the startle response and of stress-induced reductions in exploratory and social behavior, indicating attenuated stress responsivity. Acute noradrenergic reactivity to stress, measured by either tyrosine hydroxylase mRNA levels or norepinephrine release, was also attenuated in WKY rats. Thus, reduced arousal and behavioral responsivity in WKY rats may be related to deficient brain noradrenergic reactivity. This deficit may alter their ability to cope with stress, resulting in the exaggerated neuroendocrine responses and increased susceptibility to stress-related pathology exhibited by this strain.

[Role of patient travel in transmission of human African trypanosomiasis in a highly endemic area of the Ivory Coast]

Human African trypanosomosis (HAT) remains a major public health problem in Subsaharan Africa. The region around the town of Bonon in middle western Côte d'Ivoire is a highly endemic HAT zone. The purpose of this study was to assess the role of travelling of infected patients in transmission of HAT. The study population included a total of 96 patients in whom HAT had been diagnosed actively or passively between 1999 and 2000. Information on each patient's residence and workplaces, i.e. water site, and farm field, was used to calculate the mean distance traveled and mean number of places visited daily by each patient. Findings indicated that both parameters, i.e., distance traveled and number of places visited, were significantly higher for patients living in Bonon than those living in hamlets or homesteads. Based on analysis of patient movements the endemic zone could be divided into three subdivisions with different modes of disease transmission. This study was performed as a preliminary step for a larger investigation designed to allow specific targeting of HAT hot spots based mainly on a geographic information system.

Mode matching technique for highly efficient coupling between dielectric waveguides and planar photonic crystal circuits

In this paper, a mode matching technique for highly efficient coupling between dielectric silica waveguides (SWG) and planar photonic crystal (PPC) waveguides based on setting localized defects in a PPC tapered waveguide is reported. The introduction of multiple defects is designed properly depending on mode mismatching arising from the different widths of the SWG and the PPC waveguide. The procedure to obtain the optimum defects configuration is described. Transmission efficiencies above 80% at a wavelength of 1.55m are reported improving significantly the transmission efficiencies achieved with conventional PPC tapered structures without defects. Furthermore, the feasibility of the coupling technique for both input/output coupling over a large frequency band is shown.

Mechanism of CIT-6 and VPI-8 crystallization from zincosilicate gels

The crystallisation of CIT-6, a large-pore zincosilicate with the framework topology of zeolite Beta and synthesised from clear hydrogels that contain, tetraethylammonium (TEA+), Li+ and Zn2+ cations, proceeds initially through the formation of an amorphous solid that incorporates all the initial Zn species. Nucleation of the *BEA phase is effected by reorganisation of the amorphous phase, whereas crystal growth involves the incorporation of soluble species also. A highly crystalline CIT-6 material is obtained after 164 h of synthesis at 140 degrees C. Scanning electron microscopy (SEM) shows that this sample exhibits two different types of crystals: well-defined pseudo-cubic crystals and rounded crystals. The latter has a broad crystal-size distribution. If crystallisation is continued with longer synthesis times, the VPI-8 crystalline phase appears, and a new population of needle-shaped crystals is detected in the SEM images. This new crystalline phase is nucleated on the surface of the rounded CIT-6 crystals, which disappear as the crystallisation progresses, while no changes are observed in the population of pseudo-cubic CIT-6 crystals. At higher crystallisation temperatures these phase transformations are accelerated, and the formation of VPI-8 is favoured over that of CIT-6.

Effects of whole cottonseed diet and recombinant bovine somatotropin on ovarian follicles in lactating dairy cows

The effects of whole cottonseed (WCS) in the diet and the administration of bovine somatotropin (bST) on ovarian follicular dynamics and plasma progesterone (P4) concentrations were examined in cows during a period of synchronized follicular growth. Lactating Holstein cows (n = 28) were randomly assigned to treatments in a 2 x 2 factorial arrangement. Diets consisted of WCS (15% of dry matter) or no WCS, and bST at a dose of 0 or 208 mg/14 d. Dietary treatments began within 24 h of calving and bST treatments began within 7 d postpartum. Cows received GnRH at 65 +/- 3 d postpartum (d 0), PGF2alpha, (d 7), a second dose of GnRH (d 9), and were inseminated 16 h later (d 10). Ovarian changes were monitored daily by ultrasonography from d 0 to 9. On d 9,93% of cows had a preovulatory follicle and 86% ovulated. For Class 2 (6 to 9 mm) follicles, a diet x bST interaction was detected, with bST stimulating Class 2 follicles in cows fed WCS, but not in cows on the control diet. Neither diet nor bST affected numbers of Class 1 (2 to 5 mm) or Class 3 (> or = 10 mm) follicles or sizes of the subordinate and dominant follicles. During the luteal phase of the cycle, lactating cows fed WCS tended to have elevated concentrations of plasma P4, whereas bST was without effect. Plasma concentrations of high-density lipoprotein cholesterol were increased in cows fed WCS. Number and diameter of corpora lutea did not differ among treatments.