Impact of Transplantation Timing on Renal Graft Survival Outcomes and Perioperative Complications

Nighttime organ transplantation aims to decrease cold ischemia duration, yet conflicting data exists on its impact on graft function and perioperative complications. This multicenter TRANSPLANT'AFUF study including 2,854 patients, transplanted between 1 January 2011, and 31 December 2022, investigated nighttime kidney transplantation's impact (8:00 p.m.-8:00 a.m.) versus daytime (8:00 a.m.-8:00 p.m.) on surgical complications and graft survival. Overall, 2043 patients (71.6%) underwent daytime graft, while 811 (28.4%) underwent nighttime graft. No impact was observed of timing of graft surgery on graft survival with a median survival of 98 months and 132 months for daytime and nightime grafting, respectively (p = 0.1749). Moreover, no impact was observed on early surgical complications (Clavien I-II = 20.95% for DG and 20.10% for NG; Clavien III-IV-V = 15.42% for DG and 12.94% for NG; p = 0.0889) and late complications (>30 days) (Clavien I-II = 6.80% for DG and 5.67% for NG; Clavien III-IV-V = 12.78% for DG and 12.82% for NG; p = 0.2444). Noteworthy, we found a significant increase in Maastricht 3 donors' rates in nighttime transplantation (5.53% DG vs. 21.45% NG; p < 0.0001). In conclusion, nighttime kidney transplantation did not impact early/late surgical complications nor graft survival.

Prevalence of Endocrine Manifestations and GIST in 108 Systematically Screened Patients With Neurofibromatosis Type 1

Context

In patients with neurofibromatosis type 1 (NF1), guidelines suggest screening for pheochromocytoma by metanephrine measurement and abdominal imaging, which may lead to the discovery of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and their differential diagnosis, gastrointestinal stromal tumors (GISTs). Other endocrine manifestations such as follicular thyroid carcinoma and primary hyperparathyroidism have also been reported in a few cases.

Objective

This study aimed to describe prevalence and clinical presentation of these manifestations through systematic screening in a large cohort of patients.

Methods

In this monocentric retrospective study, 108 patients with NF1 were included and screened for endocrine manifestations and GISTs. Clinical, laboratory, molecular profile, pathology, and morphologic (abdominal computed tomography scan and/or magnetic resonance imaging) and functional imaging were collected.

Results

Twenty-four patients (22.2% of the cohort, 16 female, mean age 42.6 years) presented with pheochromocytomas that were unilateral in 65.5%, benign in 89.7%, and with a ganglioneural component in 20.7%. Three female patients (2.8% of the cohort, aged 42-63 years) presented with well-differentiated GEP-NETs, and 4 (3.7%) with GISTs. One patient had primary hyperparathyroidism, 1 patient had medullary microcarcinoma, and 16 patients had goiter, multinodular in 10 cases. There was no correlation between pheochromocytoma and other NF1 tumoral manifestations, nor correlations between pheochromocytoma and NF1 genotype, despite a familial clustering in one-third of patients.

Conclusion

The pheochromocytoma prevalence in this NF1 cohort was higher (>20%) than previously described, confirming the interest of systematic screening, especially in young women. The prevalence of GEP-NETs and GISTs was about 3%, respectively. No phenotype-genotype correlation was observed.

Differential impact of COVID-19 on urological surgeries in public and private institutions between 2019 and 2021 in France

INTRODUCTION

The COVID-19 pandemic disrupted all routine health care services in 2020. To date, data regarding adjustment and coverage of surgical backlog in the post-COVID era actually remains scarce. The aim of this study was to compare the number of urological procedures coded between 2019 and 2021 in public and private institutions to (i) quantify the variation in surgical activity linked to the shutdown in 2020 and (ii) study the adjustment of procedures over the year 2021.

MATERIALS AND METHODS

This is a comprehensive retrospective analysis of all urological surgeries coded between January 1, 2019 and December 31, 2021 in France. Data were extracted from the open access dataset of the national Technical Agency for Information on Hospital Care (ATIH) website. In total, 453 urological procedures were retained and allocated in 8 categories. Primary outcome was the impact of COVID-19 analyzed by the 2020/2019 variation. The secondary outcome was the post-COVID catch-up analyzed by the 2021/2019 variation.

RESULTS

Surgical activity in public hospitals dropped by 13.2% in 2020 compared to 7.6% in the private sector. The most impacted areas were functional urology, stones and BPH. Incontinence surgery did not recover at all in 2021. BPH and stone surgeries were far less impacted in the private sector, with even explosive activity in 2021, post-COVID period. Onco-urology procedures were roughly maintained with a compensation in 2021 in both sectors.

CONCLUSION

The recovery of surgical backlog was much more efficient in the private sector in 2021. The pressure on the health system associated to the multiple COVID-19 waves may generate a gap between public and private surgical activity in the future.

LEVEL OF EVIDENCE: 4

Impact du COVID-19 sur l’activité chirurgicale urologique dans les établissements de santé publics et privés sur le territoire national français entre 2019 et 2021

Objectifs

La pandémie de COVID-19 a perturbé fortement l’organisation des soins. Notre objectif était de rapporter le nombre de codages de tous les actes chirurgicaux urologiques dans les établissements de santé publics et privés français en 2019, 2020 et 2021 afin de (i) quantifier la variation d’activité chirurgicale liée à la crise en 2020 et (ii) étudier le rattrapage éventuel des actes sur l’année 2021.

Méthodes

Pour chaque acte chirurgical classant Classification commune des actes médicaux (CCAM) relatif au domaine de l’urologie, le nombre de codages réalisés en 2019, en 2020 et en 2021 en établissement public et privé a été extrait de la base de données en libre accès de l’Agence technique de l’information sur l’hospitalisation (ATIH). Les 453 actes chirurgicaux ont été répartis en 9 catégories : cancérologie, lithiase, organes génitaux externes, haut appareil, vessie, hypertrophie bénigne de prostate (HBP), traumatologie, urologie fonctionnelle (pelvi-périnéologie/neuro-urologie/incontinence), et transplantation. L’impact du COVID a été analysé par la variation 2020/2019 (année de référence), et le rattrapage post-COVID par la variation 2021/2019.

Résultats

Les établissements publics ont subi une baisse d’activité de 13,2 % en 2020, contre 7,5 % dans le privé, variable selon les thématiques (Tableau 1). La pelvi-périnéologie et les chirurgies bénignes furent sévèrement impactées, la cancérologie restant relativement préservée, en accord avec les recommandations. La chirurgie de l’HBP et de la lithiase furent beaucoup moins impactées dans le secteur privé notamment pour l’urétéroscopie.

L’analyse des données 2021 montre un rattrapage d’activité supérieur dans le secteur privé dans quasiment tous les domaines, notamment en onco-urologie, à l’exception notable des cystectomies carcinologiques. La chirurgie du prolapsus et de l’incontinence, impactés par ailleurs par les arrêtés ministériels d’encadrement des pratiques, restait réduite en 2021 sans aucun rattrapage. L’activité de transplantation restait aussi significativement réduite.

Conclusion

La diminution d’activité chirurgicale urologique fut beaucoup plus importante dans le secteur public en 2020, avec une préservation de la cancérologie. Les données 2021 montrent un rattrapage d’activité notablement plus élevé dans les établissements privés, à l’exception notable de la chirurgie de l’incontinence et du prolapsus, également impactés durant cette période par des mesures d’encadrement restrictives.

Unexpected cure of a toxic nodule in a multinodular goiter induced by immune checkpoint inhibitors: a case report

Introduction

Immune checkpoint inhibitors (ICI) are used to treat cancers including metastatic melanomas and can induce endocrine side effects. The thyroid is frequently affected with classically transient thyrotoxicosis followed by hypothyroidism. The evolution of thyroid nodules and goiters under ICI therapy is poorly described.

Case presentation

A 72-year-old male presenting with hyperthyroidism due to a toxic nodule in a multinodular goiter (MNG) started ICI therapy combining ipilimumab and nivolumab to treat metastatic melanoma. After an initial worsening of thyrotoxicosis, treated with carbimazole, he developed profound hypothyroidism, persisting after carbimazole discontinuation, needing a long-term levothyroxine supplementation. Ultrasound control performed 6 months after ICIs treatment initiation revealed diffuse thyroid atrophy with involution of all nodules. 123I-scintigraphy confirmed a destructive mechanism.

Discussion

The evolution of MNG and toxic nodules is poorly described in patients treated with ICI since systematic US evaluations are lacking. We describe for the first time a toxic nodule cured by ICI therapy inducing destructive thyroiditis.

Conclusion

Pre-existing nodules and MNG, even if toxic, are not a contraindication for ICI treatment provided the patients are carefully monitored.

Evaluation and impact of fetal physiology training on fetal heart rate analysis

INTRODUCTION

Evaluation of fetal well-being during labor is based on fetal heart rate (FHR) analysis, which requires physiology expertise. The aim of the present study was to assess medical residents' fetal physiology training in terms of theoretical knowledge, FHR interpretation, and use of second-line examinations.

METHODS

This single-center, prospective study of obstetrics and gynecology residents (N = 34) at CHU de Lille Hospital (Lille, France) was conducted from November 2017 to November 2018. Evaluation and training were conducted in three stages. First, residents' pre-training knowledge of FHR interpretation and use of fetal scalp blood sampling (FBS) was assessed using clinical cases. Second, a didactic training session on fetal physiology was delivered. Finally, post-training knowledge was evaluated using the same cases presented during pre-training. I: Pre-training, 3%, 11.8%, and 14.7% of residents considered their training on fetal physiology, FHR analysis, and second-line examinations, respectively, to be sufficient. Training significantly improved their theoretical knowledge, which was assessed using multiple-choice questions (median [interquartile range]: 1.5 [1.0-2.0] vs. 4.0 [3.0-4.5], p<0.001), and reduced the number of FBS requested (36.3% vs. 29.5%, p = 0.002). Krippendorff's alpha coefficient for the reproducibility of residents' responses improved significantly, reflecting greater homogenization of clinical practice decisions (alpha [95% confidence interval]: 0.60 [0.55-0.65] vs. 0.72 [0.67-0.76]).

CONCLUSION

Improved fetal physiology knowledge promotes more accurate FHR interpretation, better indications for second-line examinations, and greater homogenization of clinical practice decisions. Future studies should evaluate the impact of fetal physiology training on clinical practice.

Phakomatoses and Endocrine Gland Tumors: Noteworthy and (Not so) Rare Associations

Phakomatoses encompass a group of rare genetic diseases, such as von Hippel-Lindau syndrome (VHL), neurofibromatosis type 1 (NF1), tuberous sclerosis complex (TSC) and Cowden syndrome (CS). These disorders are due to molecular abnormalities on the RAS-PI3K-Akt-mTOR pathway for NF1, TSC and CS, and to hypoxia sensing for VHL. Phakomatoses share some phenotypic traits such as neurological, ophthalmological and cutaneous features. Patients with these diseases are also predisposed to developing multiple endocrine tissue tumors, e.g., pheochromocytomas/paragangliomas are frequent in VHL and NF1. All forms of phakomatoses except CS may be associated with digestive neuroendocrine tumors. More rarely, thyroid cancer and pituitary or parathyroid adenomas have been reported. These susceptibilities are noteworthy, because their occurrence rate, prognosis and management differ slightly from the sporadic forms. The aim of this review is to summarize current knowledge on endocrine glands tumors associated with VHL, NF1, TSC, and CS, especially neuroendocrine tumors and pheochromocytomas/paragangliomas. We particularly detail recent advances concerning prognosis and management, especially parenchyma-sparing surgery and medical targeted therapies such as mTOR, MEK and HIF-2 α inhibitors, which have shown truly encouraging results.

[Onco-TESE and testicular cancer]

INTRODUCTION

Fertility preservation is essential before cancer treatment. When ejaculated sperm preservation is not possible, testicular tissue can be surgically collected by Onco-TESE technic (Oncological Testicular Sperm Extraction) to isolate sperm. We report on our experience with Onco-TESE in testicular cancer patients at the Rouen University Hospital.

MATERIAL AND METHOD

Retrospective study including all pubescent men, treated for testicular cancer, uni- or bilateral, before any carcinological therapy, who have undergone Onco-TESE at the Rouen University Hospital. Fragment weight, detection of sperm or its precursors were analysed. A histological interpretation of the testicular tumor was carried out. For each positive sample, straws were kept at the French Sperm Bank.

RESULTS

Twenty-four patients had an Onco-TESE: 58.34% severe sperm alteration (SSA) and 41.36% sperm collection failure (SCF), between 1996 and 2019. The mean age was 26.6 (±5.29) years. The mean procedure and length of stay were 71minutes (±30.7) and 3.75 days (±2.83), respectively. The rate of positive testicular biopsies (TB) was 58.33% overall and 66,67% in the case of TB on tumour testis. One patient had a Clavian-Dindo III complication. The mean number of straws preserved per patient was 14.28 (±15.34) for 7.14% use.

CONCLUSION

Our results seem to confirm that Onco-TESE is an effective solution for preserving fertility in men with testicular cancer in cases of SSA or SCF.

LEVEL OF EVIDENCE

III.

[BCG strain shortage from 2012 to 2014: Evaluation of its impact on the management of patients with high-risk NMIBC]

INTRODUCTION

BCG instillations are the gold-standard treatment for high-risk non-muscle-invasive bladder cancer (NMIBC) with a decreased risk of tumor recurrence and muscle infiltration. From 2012 to 2014, a stock shortage of the Connaught strain has led to the cessation of supply for immucyst in France. The objective of this study was to evaluate the potential impact of BCG shortage on the management of patients with NMIBC.

PATIENTS AND METHODS

We conducted a retrospective single-center study including patients followed from May 2005 to May 2015 with a high-risk NMIBC (primo-diagnosis). Patients were separated into two groups: not impacted by the shortage (NISG: 56 patients) and impacted by the shortage (ISG: 53 patients). Data on tumour recurrence (RFS), muscle progression (PFS) and overall and specific survival (OS and SS) were also analysed.

RESULTS

The BCG induction schedule could not be carried out in 20.8% of cases in the ISG compared to only 5.3% of cases in NISG (P=0.02). Similarly, the maintenance treatment was incomplete for 56.6% of cases versus 37.5% in NISG (P=0.047). Nevertheless, it should be underlined that very high-risk NMIBC received a complete induction BCG schedule. The ISG seems to have benefited with the evolution of the guidelines with the use of diagnosis bladder fluorescence but without significant difference on the rate of second look bladder trans-uretral resection. The cystectomy rate was higher in ISG. No significant difference in RFS, PFS, OS, and SS between the two groups.

CONCLUSION

In our experience, RFS, PFS, OS or SS were not impacted by the BCG shortage. These data may be explained by a better selection of very high-risk patients including the recommended BCG schedule and more frequently the use of diagnosis bladder fluorescence.

LEVEL OF EVIDENCE

3.

When should foetal pH measurements be performed after a prolonged deceleration? An experimental study in a fetal sheep model

OBJECTIVE

The aim of fetal heart rate monitoring during labour is to identify and prevent foetal distress, but its evaluation is not perfect. Fetal scalp blood sampling for pH measurement is one of the second-line methods of monitoring when fetal heart rate is classified as suspicious. This study aims to determine when pH testing should be performed after a prolonged deceleration.

STUDY DESIGN

This was an experimental study in a fetal sheep model. A partial umbilical cord occlusion was performed for seven minutes followed by a recuperation period of 30 min. Hemodynamic parameters (heart rate, mean blood pressure and intra-amniotic pressure) and blood gases were recorded before occlusion (T0), during occlusion (T4), just after the end of occlusion (T7), and then 10, 20 and 30 min after occlusion (T17, T27 and T37 respectively).

RESULTS

Ten experiments were carried out. During partial cord occlusion, the fetal pH decreased significantly to acidosis. After a prolonged deceleration with fetal acidosis, the pH recovered to a normal value, defined by a pH greater than or equal to 7.25, after 20 min of recuperation.

CONCLUSION

After a prolonged deceleration, fetal pH normalizes between 20 and 30 min thereafter. Thus, if a foetal blood sample is indicated, this delay must be respected in order to avoid inducing an unnecessary intervention decision.

GSK-3β function in bone regulates skeletal development, whole-body metabolism, and male life span

Glycogen synthase kinase 3 β (GSK-3β) is an essential negative regulator or "brake" on many anabolic-signaling pathways including Wnt and insulin. Global deletion of GSK-3β results in perinatal lethality and various skeletal defects. The goal of our research was to determine GSK-3β cell-autonomous effects and postnatal roles in the skeleton. We used the 3.6-kb Col1a1 promoter to inactivate the Gsk3b gene (Col1a1-Gsk3b knockout) in skeletal cells. Mutant mice exhibit decreased body fat and postnatal bone growth, as well as delayed development of several skeletal elements. Surprisingly, the mutant mice display decreased circulating glucose and insulin levels despite normal expression of GSK-3β in metabolic tissues. We showed that these effects are due to an increase in global insulin sensitivity. Most of the male mutant mice died after weaning. Prior to death, blood glucose changed from low to high, suggesting a possible switch from insulin sensitivity to resistance. These male mice die with extremely large bladders that are preceded by damage to the urogenital tract, defects that are also seen type 2 diabetes. Our data suggest that skeletal-specific deletion of GSK-3β affects global metabolism and sensitizes male mice to developing type 2 diabetes.

Deletion of glycogen synthase kinase-3β in cartilage results in up-regulation of glycogen synthase kinase-3α protein expression

The rate of endochondral bone growth determines final height in humans and is tightly controlled. Glycogen synthase kinase-3 (GSK-3) is a negative regulator of several signaling pathways that govern bone growth, such as insulin/IGF and Wnt/β-catenin. The two GSK-3 proteins, GSK-3α and GSK-3β, display both overlapping and distinct roles in different tissues. Here we show that pharmacological inhibition of GSK-3 signaling in a mouse tibia organ culture system results in enhanced bone growth, accompanied by increased proliferation of growth plate chondrocytes and faster turnover of hypertrophic cartilage to bone. GSK-3 inhibition rescues some, but not all, effects of phosphatidylinositide 3-kinase inhibition in this system, in agreement with the antagonistic role of these two kinases in response to signals such as IGF. However, cartilage-specific deletion of the Gsk3b gene in mice has minimal effects on skeletal growth or development. Molecular analyses demonstrated that compensatory up-regulation of GSK-3α protein levels in cartilage is the likely cause for this lack of effect. To our knowledge, this is the first tissue in which such a compensatory mechanism is described. Thus, our study provides important new insights into both skeletal development and the biology of GSK-3 proteins.

First experiences with DIN ISO 14835-1 in the context of vibration-induced white finger disease

OBJECTIVES

In order to establish an international standard of cold provocation test in the assessment of vibration-induced white finger (VWF) disease, an ISO-working group tentatively created the DIN ISO 14835-1. Based on this new standard, previously existing testing conditions had to be modified. Since a comparison of current and previous evaluation procedures is necessary for both the individual assessment and the performance of metaanalyses, the revision and validation of criteria for the examination of the cold provocation tests are appropriate and necessary.

METHODS

Twenty-one individuals suffering from VWF disease whose disorder was accepted as an occupational disease underwent the cold provocation test on two successive days following a 2- and a 5-min-long exposure to the cold. As a benchmark for classification as 'normal' or 'pathological', the 15-min mark after a 2-min-long exposure was chosen. A skin temperature of 28 degrees C was selected for discrimination between 'non-pathological' (at least 28 degrees C) and 'pathological' test results.

RESULTS

It could be shown, that exposures to cold water (12 degrees C) over 2 and 5 min lead to similar rewarming profiles, who differ in median systematically by 1 degrees C. A modification of the former classification rule should be considered. After a 5 min exposure, the classification criterion can be based on the temperature assessments measured after 20 min; alternatively the cut point can be reduced from 28 to 27 degrees C while maintaining the previous assessment time of t = 15 min.

CONCLUSIONS

The shown results represent the first attempt of modifying the previous classification criteria of the cold provocation test within the scope of the VWF disease. In view of the described problems of the study design there is no doubt that continuing modifications and their validation on the base of larger collectives groups are necessary.

Different acute effects of single-axis and multi-axis hand-arm vibration

Under laboratory conditions the effects of single-axis and multi-axis hand-arm vibration exposure on several strain parameters were tested in up to 20 male subjects. As parameters of these acute effects, the biodynamic vibration behavior of the hand-arm system, the electrical activity of the most affected muscle groups, the skin temperature, the vibration sensitivity of the fingertips, and the subjective vibration sensation were measured. When comparing simulated three-axis vibration exposure with single-axis vibration exposure, synergistic effects in the form of an increasing reaction could be found. It could be proven that the vector sum of the frequency-weighted acceleration in the three axes represents the acute effects better than does the weighted acceleration in the main axis alone. This summation has to take into account the relatively lower effects of vibration in the x- or y-direction compared with the z-direction. On the basis of the experimental results a new proposal for frequency weighting of the three different axes and an energetic summation procedure are derived. Application of this knowledge in the International Standard ISO 5349 is proposed.

Experience on the reversibility of the vibration-induced white finger disease

In connection with medical appraisements of the occupational disease No. 2104 "Vibration-induced vasospastic disease" 240 patients could be examined a first time, 94 of them a second time, 42 patients a third time and 11 patients a forth time. The interval between examinations was 2, 4 or 6 years respectively. The standard procedure besides clinical whole body examination included anamnestic questionnaire, cold-provocation test with infrared thermography and vibrotactile perception test. The evaluation of the diagnoses in principle followed the Stockholm vascular V and sensorineural SN stages and was used to establish the grade of disability for compensation. The re-examinations after 2-6 years gave information on the development of the health status after cessation of vibration exposure. In only about 54% of all cases there was any improvement, in 39% the health status was unchanged, in 7% aggravated. It is obvious that the reversibility of the VWF if any needs many years abstaining from vibration exposure.

The vibrotactile threshold (VT) at the fingertips of chain saw operators

The vibration sensitivity of the skin at the ten fingertips was tested with 72 chain saw operators examined due to VWF-disease and compared with controls. The vibrotactile perception threshold (frequency f = 125 Hz, load p = 1.3 N) proved to be 3 to 5 times as high for the exposed group compared to controls. There was no correlation between vibration sensitivity and peripheral circulation found in cold provocation test. Two different testing instruments (pallaesthesiometer = vibrotactometer) showed significant differences in results probably due to different technical details of the methods. It may be concluded that a standardization of the instrumentation and method is necessary for testing the vibrotactile perception threshold as a part of the nervous function in a comparable manner.

Medical and occupational preconditions for vibration-induced spinal disorders: occupational disease no. 2110 in Germany

The current state of scientific knowledge of the biodynamic behaviour of the vertebral column under the influence of whole-body vibration whilst sitting and results from epidemiological studies caused the medical board of experts on occupational health of the Federal Ministry of Labour in Germany to add a new occupational disease to the official list of occupational diseases. The occupational disease "diseases of the lumber spine from disc degeneration caused by long-term (mainly vertical) whole-body vibration exposure" has been introduced. The medical preconditions with the symptoms and the diagnostic methods are presented. With regard to the occupational preconditions for the acknowledgement of this occupational disease, a procedure is suggested which leads to the determination of the total occupational vibration exposure dose. Another requirement for recognition is that the chronic recurrent complaints have caused the patient to avoid any form of vibration exposure.

Effects of grip and push forces on the acute response of the hand-arm system under vibrating conditions

The purpose of the occupational medicine component of a joint research project was to study the effects of grip and push forces on the acute reaction of the hand-arm system under vibrating conditions. Several series of experiments were carried out by means of a vibration simulator in a laboratory environment in order to study biodynamic vibration behaviour, muscle response, skin temperature, shifts of the vibration perception threshold and the intensity of subjective vibration perception; in addition, field tests with hammer drills were conducted. On the whole, the findings obtained suggest that the coupling of the hand with the handle involved in using vibrating tools has a considerable impact on the stresses to which the hand-arm system is exposed. For this reason, future national and international rules and regulations on vibration assessment should take into consideration the effects of variations in coupling intensity.

Acute effects of transient vertical whole-body vibration

The question as to whether shock-type whole-body vibration causes increasingly acute strain was investigated. Random vibrations were superimposed with shocks differing in amplitude and in number per unit of time in a systematic manner. The weighted root mean square (rms) acceleration was kept constant in all over the varied experiments. A total of 17 men were exposed to vibration from an electrohydraulic simulator. The following strain criteria were used: biodynamic behavior of the trunk and the head, electrical activity of the muscles of the back and the neck, subjective sensation, skin temperature in the lumbar area and visual and tracking performance. It was found that increasing shock amplitude and, in some experiments, also increasing numbers of shocks led to increasingly acute effects that varied, depending on the kind of shock used. New methods should be developed for the assessment of transient vibration that are better than the existing standards.

[The effect of mechanical vibration on the spinal column]

Drivers of trucks, earth-moving equipment, fork-lift trucks, agricultural tractors and military vehicles are often exposed to a high amount of vibration. The stress-strain model is helpful for demonstrating the effects as the biodynamic behavior of the seated workers is important. Epidemiological research draws our attention to the danger involved for the lumbar spine from mechanical vibration. Prevention measures are given.

[Disorders in peripheral circulation and nerve function caused by working with hand-operated vibrating tools]

So far, there are only hypotheses about the etiology of vibration-caused vasospastic syndrome (VVS). When assessing the occupational stress, one must consider the kind, intensity and duration of the exposure to vibration, the static forces, environmental temperature, and noise. The symptoms peculiar to this disease are vasospastic attacks with white fingers, numbness and local pain. The diagnostic methods include a general medical examination, an anamnesis and special tests (cold provocation with measurements of finger-tip temperature or infrared thermography). Epidemiological research has enabled us to establish dose-effect relationship. Appropriate preventive measures may reduce the risk of VVS.

Biodynamic behavior of the trunk and the abdomen during whole-body vibration

Vibration strain may be defined as the sum of all reactions of the human being to vibration exposure. This also includes the biomechanical behavior of particular parts of the body. Knowledge about these reactions is necessary in the field of occupational health and ergonomics. Biomechanical models, experimental methods, and results are presented. It can be shown that under vibration exposure with different conditions (body posture, vibration direction), the body parts are in resonance at varying frequencies, mainly in a low frequency range.

Effects of combined hand-arm vibration and cold on skin temperature

Under laboratory conditions 14 healthy male subjects were exposed to hand-arm vibration (ahzw = 6.3 m/s2) at different air temperatures (5 degrees, 12 degrees, 18 degrees and 25 degrees C). Static load (grip force 15 N, push force 40 N) was kept constant. Finger tip temperature as an indirect criterion of the peripheral blood circulation was measured. As expected, low air temperatures (5 degrees, 12 degrees and 18 degrees C) cause a strong decrease of skin temperature. Under additional stress of vibration connected with static load, a further decrease of the mean skin temperature was noted. At this, static load proved to have a predominant influence on the acute diminution of skin temperature. The individual reaction to the stressors varied considerably. Field tests during practical work with a chain saw at low air temperatures showed results similar to those of the laboratory tests. The protective effect of a grip heating system could be demonstrated.

Thermographic assessment of skin temperature during a cold provocation test

A description was made of the development and application of infrared thermography and fingertip thermometry for the assessment of finger skin temperature during a cold provocation test. Three hundred and seventeen lumberjacks, grinders, metalworkers, stone cutters, and students were examined in laboratory and field investigations. Under laboratory conditions, the influence of water temperature and exposure duration was studied, and skin temperature measurements were made on the volar and dorsal side of the fingers. In the field occupational health examination, infrared thermography and fingertip thermometry were simultaneously applied during a cold provocation test. The following three types of temperature reaction could be recognized: normal rewarming and moderate delay and strong delay of rewarming. The temperature distribution along the finger length was analyzed. The following conclusions were drawn for practical application of the thermometric methods. Skin temperature must be measured on all 10 fingertips, either on the volar or on the dorsal surface. Fingertip thermometry may be used in occupational health examinations. Infrared thermography may yield more information on the development of disturbances in peripheral circulation along the finger length and may be used in special clinical work.

Whole-body vibration and disorders of the spine

This cross-sectional study is based on interviews and medical examinations of 352 operators of earth-moving machines who had been exposed to whole-body vibrations for at least three years. In addition, available X-rays showing different parts of the spines of 251 machine operators who had been exposed to vibration for at least ten years were used for evaluation. One hundred and forty-nine of the operators were asked about discomfort occurring immediately after an eight-hour work shift. The group of exposed persons was compared with a control group of 215 non-exposed persons. The percentage of subjects reporting spinal discomfort was much higher for the exposed group than for the non-exposed group. 68.7% of the operators complained of spinal discomfort in the lumbar spine, 6.8% in the thoracic column and 18.2% in the cervical column. The discomfort reported immediately after an eight-hour exposure to whole-body vibration was highly age-dependent. The epidemiological study resulted in an objective conformation of the spinal discomfort reported, 2/3 of which were related by the operators to the lumbar syndrome. Lumbar syndrome (81%) accounted for by far the highest number of spinal disorders. Examinations of the operators with at least ten years of exposure to whole-body vibrations showed that morphological changes in the lumbar spine occur earlier and much more frequently than in the case of non-exposed persons. Problems of etiology and pathogenesis are discussed.

Acute effects of shock-type vibration transmitted to the hand-arm system

The aim of the project was to find out whether shock-type vibration of hand-tools compared to non-impulsive vibration has stronger acute effects on the hand-arm system and therefore needs a stricter evaluation from the occupational health point of view in comparison with the requirements of the Draft International Standard ISO-DIS 5349. Under laboratory conditions, subjects were exposed to simulated vibration of hand-tools (grinder, chain saw, hammer-drill, pneumatic hammer, rivet hammer and nailer). The following evaluation criteria were used: biomechanical transmissibility of the hand-arm system (wrist, elbow joint, shoulder joint); muscle-activity (m. flexor carpi ulnaris, m. biceps, m. triceps); peripheral circulation (skin temperature) and subjective perception (comparison of intensity of standard and test vibrations). The results show no significant difference in acute effects on the hand-arm system between impulsive and non-impulsive type vibrations of the hand-tools tested with respect to the chosen vibration level, short-time exposure (up to 8 min) and evaluation criteria. In summary, therefore, it may be concluded that for the evaluation of shock-type vibration of the hand-tools tested, it is justified to use the existing Draft International Standard ISO-DIS 5349.

[Orthostatis stress from standing at work]

The evaluation of different body postures during work needs considering the interactions of anthropometric, physiological, orthopaedic, angiologic and biomechanical criteria on one side and of working conditons on the other. Many professions in industry as well as many tasks of the housewife still have to be done in standing position. But standing for long periods leads to increased strain of the bone and muscle system and to increased complaints and illness of the feet and legs. A comprehending catalogue of the effects of dominating standing posture and a catalogue of preventive measures are presented.

[Research on the biomechanical vibration behaviour of man's bulbi (author's transl)]

Mechanical vibration may lead to a decrease in visual performance. This may be expected if the natural frequency of the eye is excited. Experiments wit eight subjects and one repeat were carried out with the aim of calculating the biomechanical transmission of vibration between the cranium and the eye. The oscillation of the reflex-point of the cornea and of a light-point on the forehead were observed by a TV-camera and recorded using a multipoint-X-Y-tracker-system with a direct writer. The analysis showed typical resonance curves for the eye with maxima at 25-31.5 Hz typical to those found in animal experiments using other methods. Therefore at places of work transmission of such vibration frequencies to the head should be avoided to prevent a decrease in visual performance.

[Animal experiments on the biomechanical vibration behaviour of the bulbus (author's transl)]

Mechanical vibration may have a detrimental effect on visual performance. This particularly seems to be the case if the natural frequency of the bulbus is excited. Experiments with animals were made with the aim of calculating the biomechanic transmission of vibration between the cranium and bulbus. Postmortem experiments using pig crania have shown that in vivo application of the method of sewing miniature accelerometers onto the cornea may be possible. Our experiments with monkeys gave typical resonance curves for the transmission of vibration of the bulbi with maxima between 25 and 31.5 Hz. Transferability of the results to the human eye is discussed.

[Mechanical factors contributing to the cause of retinal detachment (author's transl)]

There is no doubt that besides the anatomical changes in vitreous and retinal structures mechanical factors are involved in producing retinal detachment. Especially vertical accelerations can produce fast movements of the vitreous, which also can induce the retina. To investigate the effect of various external movements upon the eye a number of experiments were made: 31 variations of movements with and without different vehicles at different speeds have been investigated. As direct measurements of acceleration of the eye are not possible at present, the upper verges of the orbitae were chosen as measuring point. Additionally accelerations were measured nearest to the place of the entrance of vibration to the body in order to examine the transmissibility of vibration to the orbita. The transduced signal of the accelerometer was recorded on a tape. When measuring in vehicles or riding, radiotelemetry of the signal was used. The statistical analysis of the results was performed. Typical frequencies were found in which the amplitude of the induced acceleration even is enlargen on its way through the body to the orbita. The significance of the different results for producing dangerous mechanical stress to the eye is discussed.