High-Speed On-Site Deep Learning-Based FFR-CT Algorithm: Evaluation Using Invasive Angiography as the Reference Standard

BACKGROUND. Estimation of fractional flow reserve from coronary CTA (FFR-CT) is an established method of assessing the hemodynamic significance of coronary lesions. However, clinical implementation has progressed slowly, partly because of off-site data transfer with long turnaround times for results. OBJECTIVE. The purpose of this study was to evaluate the diagnostic performance of FFR-CT computed on-site with a high-speed deep learning-based algorithm with invasive hemodynamic indexes as the reference standard. METHODS. This retrospective study included 59 patients (46 men, 13 women; mean age, 66.5 ± 10.2 years) who underwent coronary CTA (including calcium scoring) followed within 90 days by invasive angiography with invasive fractional flow reserve (FFR) and/or instantaneous wave-free ratio measurements from December 2014 to October 2021. Coronary artery lesions were considered to have hemodynamically significant stenosis in the presence of invasive FFR of 0.80 or less and/or instantaneous wave-free ratio of 0.89 or less. A single cardiologist evaluated the CTA images using an on-site deep learning-based semiautomated algorithm entailing a 3D computational flow dynamics model to determine FFR-CT for coronary artery lesions detected with invasive angiography. Time for FFR-CT analysis was recorded. FFR-CT analysis was repeated by the same cardiologist in 26 randomly selected examinations and by a different cardiologist in 45 randomly selected examinations. Diagnostic performance and agreement were assessed. RESULTS. A total of 74 lesions were identified with invasive angiography. FFR-CT and invasive FFR had strong correlation (r = 0.81) and, in Bland-Altman analysis, bias of 0.01 and 95% limits of agreement of -0.13 to 0.15. FFR-CT had AUC for hemodynamically significant stenosis of 0.975. At a cutoff of 0.80 or less, FFR-CT had 95.9% accuracy, 93.5% sensitivity, and 97.7% specificity. In 39 lesions with severe calcifications (≥ 400 Agatston units), FFR-CT had AUC of 0.991 and at a cutoff of 0.80, 94.7% sensitivity, 95.0% specificity, and 94.9% accuracy. Mean analysis time per patient was 7 minutes 54 seconds. Intraobserver agreement (intraclass correlation coefficient, 0.85; bias, -0.01; 95% limits of agreement, -0.12 and 0.10) and interobserver agreement (intraclass correlation coefficient, 0.94; bias, -0.01; 95% limits of agreement, -0.08 and 0.07) were good to excellent. CONCLUSION. A high-speed on-site deep learning-based FFR-CT algorithm had excellent diagnostic performance for hemodynamically significant stenosis with high reproducibility. CLINICAL IMPACT. The algorithm should facilitate implementation of FFR-CT technology into routine clinical practice.

Radiomics for the detection of diffusely impaired myocardial perfusion: A proof-of-concept study using 13N-ammonia positron emission tomography

AIM

The current proof-of-concept study investigates the value of radiomic features from normal 13N-ammonia positron emission tomography (PET) myocardial retention images to identify patients with reduced global myocardial flow reserve (MFR).

METHODS

Data from 100 patients with normal retention 13N-ammonia PET scans were divided into two groups, according to global MFR (i.e., < 2 and ≥ 2), as derived from quantitative PET analysis. We extracted radiomic features from retention images at each of five different gray-level (GL) discretization (8, 16, 32, 64, and 128 bins). Outcome independent and dependent feature selection and subsequent univariate and multivariate analyses was performed to identify image features predicting reduced global MFR.

RESULTS

A total of 475 radiomic features were extracted per patient. Outcome independent and dependent feature selection resulted in a remainder of 35 features. Discretization at 16 bins (GL16) yielded the highest number of significant predictors of reduced MFR and was chosen for the final analysis. GLRLM_GLNU was the most robust parameter and at a cut-off of 948 yielded an accuracy, sensitivity, specificity, negative and positive predictive value of 67%, 74%, 58%, 64%, and 69%, respectively, to detect diffusely impaired myocardial perfusion.

CONCLUSION

A single radiomic feature (GLRLM_GLNU) extracted from visually normal 13N-ammonia PET retention images independently predicts reduced global MFR with moderate accuracy. This concept could potentially be applied to other myocardial perfusion imaging modalities based purely on relative distribution patterns to allow for better detection of diffuse disease.

Post-hoc motion correction for coronary computed tomography angiography without additional radiation dose - Improved image quality and interpretability for “free”

Objective

To evaluate the impact of a motion-correction (MC) algorithm, applicable post-hoc and not dependent on extended padding, on the image quality and interpretability of coronary computed tomography angiography (CCTA).

Methods

Ninety consecutive patients undergoing CCTA on a latest-generation 256-slice CT device were prospectively included. CCTA was performed with prospective electrocardiogram-triggering and the shortest possible acquisition window (without padding) at 75% of the R-R-interval. All datasets were reconstructed without and with MC of the coronaries. The latter exploits the minimal padding inherent in cardiac CT scans with this device due to data acquisition also during the short time interval needed for the tube to reach target currents and voltage (“free” multiphase). Two blinded readers independently assessed image quality on a 4-point Likert scale for all segments.

Results

A total of 1,030 coronary segments were evaluated. Application of MC both with automatic and manual coronary centerline tracking resulted in a significant improvement in image quality as compared to the standard reconstruction without MC (mean Likert score 3.67 [3.50;3.81] vs 3.58 [3.40;3.73], P = 0.005, and 3.7 [3.55;3.82] vs 3.58 [3.40;3.73], P < 0.001, respectively). Furthermore, MC significantly reduced the proportion of non-evaluable segments and patients with at least one non-evaluable coronary segment from 2% to as low as 0.3%, and from 14% to as low as 3%. Reduction of motion artifacts was predominantly observed in the right coronary artery.

Conclusions

A post-hoc device-specific MC algorithm improves image quality and interpretability of prospectively electrocardiogram-triggered CCTA and reduces the proportion of non-evaluable scans without any additional radiation dose exposure.

The Use of Echolocation as a Mobility Aid for Blind Persons

This study concerns echolocation as a viable means for the enhancement of mobility for visually impaired and blind persons. The experimental group: five totally blind subjects, one with light perception only; the control group: eleven sighted, blindfolded subjects. Results showed a significant difference between the two groups’ ability to identify obstacles correctly using reflected sounds (echoes) with the experimental group being much more proficient.

[Bariatric surgery in children and adolescents]

Obesity in childhood and adolescents has gained epidemic proportions; in Germany 15-20 % of boys and girls are overweight, more than 6 % are known to be obese. By now, 25 % of relevant people show a pathological glucose intolerance, 4-5 % are developing type 2 diabetes mellitus (T2DM). In addition, metabolic disorders leading to hypertension and cardiac, renal or ophthalmological complications could be named as serious comorbidities. Medical and behavioural intervention as treatment for obesity in childhood remains largely ineffective: 5-10 % weight loss within 2 years rarely results in significant durable success. In adults, bariatric surgery is being used increasingly as an effective approach to achieve weight loss and to improve serious medical comorbidities, in particular T2DM. Enhancement of quality of life and explicit extension of survival are concomitant phenomenons. To date, a range of different types of bariatric procedures has been performed in adolescents, but studies evaluating and analysing preoperative data, postoperative course and follow-up in a representative number of patients younger than 18 years are still lacking. Nevertheless, current experience suggests significant weight loss and improving obesity-related medical comorbidities after bariatric surgery in adolescents too. Moreover, bariatric surgery in adolescents seems to induce less complications and a shorter hospital stay than in adults. Al-though surgical therapy for obesity in this group of patients remains an individual decision, even though explicit guidelines have been published specifying inclusion and exclusion criterias. Analysis of our own patient group and results of the study of the quality assurance "surgical treatment of morbid obesity" are appropriate tools to evaluate surgical techniques and to provide long-term follow-up.

The c-Jun N-terminal kinase (JNK) inhibitor XG-102 enhances the neuroprotection of hyperbaric oxygen after cerebral ischaemia in adult rats

AIM

Both hyperbaric oxygenation (HBO) and inhibition of the c-Jun N-terminal kinases (JNKs) by the peptide inhibitor XG-102 (D-JNKI-1) are efficient protective strategies against ischaemia-induced neurodegeneration. The present study investigated whether the combination of HBO and JNK inhibitor, XG-102, provides additive neuroprotection against cerebral ischaemia.

METHODS

Rat middle cerebral artery was occluded (MCAO) for 90 min. XG-102 [2 mg/kg, intraperitoneally] or HBO (3 ATA, 60 min) was applied 3 h after the onset of MCAO. For the combination treatment, HBO was started 10 min after the injection of XG-102. Twenty-four hours after MCAO, the infarct area, the neurological score and the immunohistochemistry staining in brain slices for cleaved-PARP, transferase-mediated biotinylated UTP nick end labelling, c-Jun and phosphorylated (activated) c-Jun were observed.

RESULTS

XG-102 or HBO alone reduced the total infarct area by 43% and 63%, respectively. The combination diminished total infarct area by 78%, improved the neurological function and reduced brain oedema. Co-application of HBO and XG-102 also significantly reduced the cleavage of PARP, by 96% and 91% in cortical penumbra and ischaemic core, respectively. Moreover, cotreatment significantly attenuated the number of cells labelled with transferase-mediated biotinylated UTP nick end labelling and phosphorylated c-Jun.

CONCLUSION

Our study demonstrates that HBO reinforces the efficiency of neuroprotective drugs such as XG-102 and vice versa. Both treatments, physical HBO and pharmacological XG-102, are already in phase I/II studies and promising strategies for clinical use.

Recurrent intussusceptions in an infant that were terminated by laparoscopic ileocolonic pexie

For children with ileocolic intussusceptions, laparoscopy has been proposed as an emergency intervention, but it has not been elaborated for elective prevention of recurrencies. We report about an infant who developed his first ileocolic intussusception at the age of 12 months. Radiologic devagination was successful, but had to be repeated for two consecutive recurrences within several days. Six months later, he presented with another episode of intussusception, which again was managed conservatively. At this time, preventive surgery seemed indicated. Diagnostic laparoscopy using three trocars and 5-mm instruments showed an insufficient closure of the ileocecal valve, allowing the surgeon easily to provoke an intussusception. Consequently, the distal ileum was attached to the ascending colon with several interrupted 3-0 sutures. The infants postoperative course was uneventful. Oral feeding was started immediately, and he could be discharged after 3 days. Within a follow-up period of 1 year, no evidence of intussusception was noted. We conclude that for children with recurrent episodes of intussusception, laparoscopic ileocolonic pexie presents a beneficial strategy for protective surgery.

Critical validation of colour Doppler ultrasound in diagnostics of acute scrotum in children

Acute scrotum in children is generally a symptom. Several pathologies of the testis, scrotum or groin may cause it, including inflammatory as well as ischaemic processes. Testicular torsion with ischaemia of the testis is an emergency requiring prompt surgical intervention. Even experienced paediatric surgeons and urologists may have difficulties differentiating an ischaemic from an inflammatory aetiology solely on the basis of clinical signs and symptoms. In cases of aetiologic uncertainty, operative exploration has to be performed to rule out ischaemia, which led in the past to a high rate of surgery. More recently, colour Doppler ultrasonography (CDUS) has become an imaging modality for the examination of the acute scrotum with the purpose of detecting ischaemia, thus reducing the need for explorative surgery. In this study we examined the reliability of CDUS, comparing the sonographical diagnoses with both the intraoperative findings and the clinical course. We present here 132 consecutive cases of acute scrotum in children, who were admitted from 01/98 through 10/02 to our hospital. All patients underwent CDUS. Patients with ultrasonographic signs of ischaemia of the testis (group A) and patients with demonstrated perfusion and suspicious or severe clinical symptoms (group B) were operated immediately. Patients with demonstrated perfusion without suspicious or severe symptoms (group C) were treated conservatively. Thirty-eight patients (28.8%) were treated operatively. Eleven cases of testicular torsion in group A (12 pat.) could be confirmed intraoperatively, in one case there was no testicular torsion but a severe inflammation of the testis with torsion of the appendix testis. In group B (26 pat.) operative exploration revealed one case of testicular torsion. In group B two cases of sonographically suspected torsions of the appendix testis also emerged as epididymitis intraoperatively. In the other cases postoperative diagnosis was in agreement with the preoperative CDUS. The clinical course of 94 conservatively treated patients (71.2%) (group C) confirmed in all cases a non-ischaemic aetiology. There was a total of 12 cases (9.1%) where acute scrotum was caused by testicular torsions. This relatively low rate underlines the necessity to differentiate between ischaemic and other aetiologies, thus avoiding operation in many patients. 71.2% of our patients could be treated conservatively. However, it is essential to exclude an ischaemic cause before opting for conservative therapy. Even though CDUS is a very valuable diagnostic tool in this sense, this exclusion cannot be ensured in every case and is highly dependent on the expertise and technique of the investigator. Therefore in cases with any doubts an operative exploration has to be performed to avoid the most dreaded complication in the treatment of acute scrotum.

Ileoileal intussusception caused by a Ewing sarcoma tumour. An unusual case report

Intussusception typically occurs in childhood, presenting with a well-known medical history and clinical symptoms. Pathologically, a "leading point" may be attributed to lymphadenomatosis, polyps, or a tumour. In older patients and adolescents, the diagnosis can be complicated due to the lower incidence and variable subacute symptoms. We report on an 18-year-old patient with increasing abdominal discomfort over several weeks. External diagnostics showed no pathological signs or were misinterpreted as a malfunction of intestinal motility. The patient experienced increasing colics, recurrent vomiting, dehydration and weight loss. Finally he was transferred to our paediatric surgical department and laparotomy had to be performed for the clinical and radiological signs of an ileus. An ileoilealic intussusception was found, caused by a small bowel tumour, which almost completely obstructed the intestinal lumen. It was resected and bowel continuity was re-established. Histopathology revealed a very rare, highly malignant mesenchymal Ewing sarcoma, infiltrating the complete bowel wall. After the postoperative course, the patient was transferred to our oncological department for chemotherapy. In older children or young adults, intestinal malignancies are extremely rare. Nevertheless, if these patients suffer from unspecific complaints of chronic intestinal obstruction, a tumour must be ruled out. A Ewing sarcoma may be responsible for an intussusception.

Postpericardiotomy syndrome after minimally invasive pectus excavatum repair unresponsive to nonsteroidal anti-inflammatory treatment

A 14-year-old boy developed postpericardiotomy syndrome after an otherwise uneventful minimally invasive pectus excavatum repair. Dyspnoea, chest pain, and pericardial effusion progressed despite nonsteroidal anti-inflammatory treatment. The symptoms rapidly resolved with intravenous methylprednisolone, and pericardiocentesis was thus avoided. This is the first report of postpericardiotomy syndrome after the Nuss procedure treated with systemic steroids.

Laparoscopic resection of a congenital liver cyst and simultaneous closure of a diaphragmatic defect in a 5-month-old infant

Congenital liver cysts are an unusual finding and present a difficult diagnostic challenge. In a 5-month-old infant, routine echocardiography detected a cystic lesion (3 cm in diameter) just below the diaphragm. All conventional diagnostics, including magnetic resonance imaging (MRI), failed to clarify its etiology definitively. Moreover, a phrenic irregularity was suspected at the site of Morgagni. Finally, laparoscopy (5-mm scope and instruments) confirmed the diagnosis of a solitary liver cyst and a diaphragmatic defect. Using a Harmonic scalpel, the cyst was resected and the diaphragmatic defect was closed with interrupted nonabsorbable sutures. The patient's postoperative course was uneventful. Pathological analysis showed a true liver cyst with mesothelial lining and hepatic residues. Retrospective speculation suggests a common embryologic origin for both malformations. In conclusion, laparoscopy allowed final diagnosis and simultaneous treatment of an infant with the rare combination of a liver cyst and a diaphragmatic defect. To our knowledge, this case represents the first endosurgical experience of such a simultaneous procedure.

Laparoscopic repair of an extrahiatal hernia caused by congenital dysplasia: a case report

A 40-year-old woman with complaints of relapse in the upper abdomen and dysphagia was referred for laparascopic hiatal hernia repair. Chest radiograph, barium-swallow, and upper endoscopy revealed a paraesophageal hernia. Esophageal manometry and 24-h-pH study showed no pathological findings. A laparoscopic gastropexy was planned. Intraoperatively, in contradiction to the preoperative findings, an extrahiatal hernia containing most of the stomach was found. After resection of the hernia sac, the beating heart without covering pericardium was seen. These findings were confirmed by an additional thoracoscopy at the end of the operation. The defect was closed by direct suturing. The postoperative course and 2-month follow-up were uneventful. The resected parts of the hernia sac showed an embryonic and dysgenetic etiology. This rare malformation has been reported in combination with complex syndromes, which appear with serious clinical and morphological signs in the neonatal period. In adults, the pericardial aplasia can be observed during diagnostic or surgical interventions. In these patients, complaints are usually not caused by the malformation but may be due to the occasional herniation of abdominal organs. We consider laparoscopic repair to be a gentle and safe procedure for the treatment of extrahiatal hernias.

Multiple intestinal stenoses and peripheral gangrene: a combination of two rare surgical complications in a child with Kawasaki disease

Kawasaki disease (KD) often presents with a challenging variety of clinical symptoms. Severe gastrointestinal complications are rare and mainly appear as pseudo-obstruction. However, the authors report the unique case of a 4-month-old girl with KD suffering from a mechanical ileus. The optimal timing of surgery presented a dilemma, because she received lytic treatment for gangrenes of both her hands and feet and additionally had large coronary artery aneurysms. Finally laparotomy had to be performed while the patient was on an anticoagulant medication, and it showed a 30-cm-long jejunal segment with multiple filiforme stenoses, requiring resection and anastomosis. The postoperative course was uneventful regarding the abdominal situation; however, the left hand and left foot remained gangrenous and had to be amputated. In patients with KD, not only pseudo-obstruction, but irreversible intestinal obliteration has to be encountered. This combination of intestinal stenosis and acral gangrene has not been described before. J Pediatr Surg 36:651-653.

Active expression of the ubiA gene from E. coli in tobacco: influence of plant ER-specific signal peptides on the expression of a membrane-bound prenyltransferase in plant cells

The ubiA gene from E. coli codes for 4-hydroxybenzoate: polyprenyldiphosphate 3-polyprenyltransferase, an integral membrane protein involved in ubiquinone biosynthesis. This prokaryotic membrane protein was stably expressed in tobacco using Agrobacterium tumefaciens-mediated transformation. Transgenic lines containing a direct fusion of the ubiA structural gene to a 35S-derived promoter gave very low enzyme activity levels (average 0.16 pkat/mg). Inclusion of an N-terminal ER-specific signal peptide from a lectin gene from Phaseolus vulgaris resulted in an average activity of 1.08 pkat/mg in the transgenic tobacco lines. The additional inclusion of a C-terminal HDEL tetrapeptide, responsible for the retention of proteins in the endoplasmic reticulum of eukaryotic cells, increased the activity to 18.6 pkat/mg. When the promotor of this construct was changed from the 35S derivative to the recently described very strong plant promoter (ocs)3mas, the activity increased further to 128.6 pkat/mg. The most active tobacco line showed activities of the introduced enzyme which exceeded those of wild-type E. coli (the source of ubiA) by a factor of 1100. These results demonstrate the efficacy of plant ER-specific signal peptides for the active expression of a prokaryotic membrane protein in plants.

Genetic engineering on shikonin biosynthesis: expression of the bacterial ubiA gene in Lithospermum erythrorhizon

The naphthoquinone pigment shikonin from Lithospermum erythrorhizon Sieb. et Zucc. (Boraginaceae) was the first plant secondary metabolite produced in industrial scale from plant cell cultures. We have now manipulated the biosynthetic pathway leading to shikonin in L. erythrorhizon by introduction of the bacterial gene ubiA. This gene of Escherichia coli encodes 4-hydroxybenzoate-3-polyprenyltransferase, a membrane-bound enzyme that catalyzes a key step in ubiquinone biosynthesis. Using geranyl diphosphate (GPP) as substrate, it is able to catalyze the formation of 3-geranyl-4-hydroxybenzoate (GBA), a principal step of shikonin biosynthesis. The prokaryotic ubiA gene was fused to two signal sequences for targeting of the resulting peptide to the endoplasmic reticulum (ER). Constructs with different constitutive promoters were introduced into L. erythrorhizon using Agrobacterium rhizogenes-mediated transformation. In the resulting hairy root lines, high UbiA enzyme activities could be observed, reaching 133 pkat mg(-1). Expression of ubiA resulted in an accumulation of GBA in an amount exceeding that of the control culture by a factor of 50. However, the ubiA-transformed lines showed only a marginal (average 22%) increase of shikonin production in comparison to the control lines, and there was no significant correlation of UbiA enzyme activity and shikonin accumulation. This suggests that overexpression of ubiA alone is not sufficient to increase shikonin formation, and that further enzymes are involved in the regulation of this pathway.

Proliferation, zonal maturation, and steroid production of fetal adrenal transplants in adrenalectomized rats

The present study investigated the histologic maturation, proliferative capacity, and steroid production of fetal adrenal transplants (Tx) in adrenalectomized rats. A pair of fetal adrenal glands (18-20 days of gestation) was transplanted into the omentum of syngeneic Lewis rats (n = 45). Four weeks later, in 5 animals the grafts were excised for morphologic evaluation. Proliferation was investigated by immunohistochemical staining for KI-67 protein and quantified by the proliferation index (PI = positive cells/100 counts). All other hosts (Tx; n = 40) underwent bilateral adrenalectomy (AE) to induce Addisonian crisis. Postoperatively, survival and concentrations of potassium, sodium, aldosterone, and corticosterone were recorded for 6 months. These data were compared to controls (C=only AE; n = 30) and a sham group (S; n = 10). At the end of the study period all surviving hosts were killed for histologic examination of grafts. At 4 weeks post-Tx the adrenal grafts demonstrated a distinct zona glomerulosa and frequent proliferation with a PI of 0.084, comparable to normal control (0.092). Following AE survival was significantly prolonged in Tx (86% vs 12% of C, P < 0.05). Control animals developed severe hyponatremia and hyperkalemia, whereas in Tx only transient signs of Addisonian crisis were recorded. Levels of aldosterone dropped within 7 days in the Tx and C groups, but returned to normal for Tx within 8 weeks. Corticosterone levels of Tx animals fell to 25% within week, but steadily increased to 70% by the end of the study. At 6 months, grafts revealed a mature adrenocortical structure with little proliferative activity, which was comparable to controls. In a syngeneic rat model fetal adrenal transplants thus mature and proliferate to provide sufficient steroid production for adrenalectomized hosts.

Laparoscopy combined with conventional operative techniques

In order to establish minimal invasive methods further, it should be guaranteed that laparoscopy is not only performed in a few pediatric surgical centers. A simple approach to gain experience would be the performance of diagnostic laparoscopy. However, benefit could be increased if the surgeon combines the minimal invasive laparoscopy to establish the diagnosis with the conventional surgical technique to continue. This approach for example applies to complicated cases of appendicitis. In a combined procedure, even bowel resections and tumor extirpations can be performed with minimal invasion. In twenty-seven cases--11 appendicectomies, 14 resections of cystic ovarian tumors and 2 resections of Meckel's diverticulum--we applied this technique and found no complications so far. The surgical method presented is convenient and safe.

Ventriculoscopy-aided implantation of ventricular shunts in patients with hydrocephalus

Ventriculoscopy represents a new concept in the surgical treatment of children with hydrocephalus. Optimal catheter position can now be achieved with the help of a new method consisting of endoscopically controlled implantation of ventricular shunts. In addition, interventional ventriculoscopy enables or improves new operative procedures such as the fenestration of intracranial cysts or the removal of dislodged parts of catheter tips from the corresponding ventricle under direct optical control. Ventriculoscopy has been performed on 17 pediatric patients, with no complications to date.

Changes in the nature of inpatient medical services--impact on medical education and patient care

One hundred sequential admissions to an internal medicine department in a 765-bed teaching hospital in 1973 were compared to 100 admitted in 1987. Mean age in 1973 was 50.3 years as compared to 57.4 in 1987. Length of stay shortened from 8.8 days in 1973 to 4.7 days in 1987. The overwhelming majority of the admissions during both periods had circulatory and/or respiratory disease. The number of diagnoses on admission increased from 2.3 in 1973 to 3.8 in 1987. In 1973, 22% of the patients received no drugs as compared to 6.3% in 1987. X-ray studies per hospital day doubled and invasive procedures more than quintupled. Intravenous fluids were given on 2.5% of days in 1973 and on 22.3% in 1987. Thus medical patients are now older and sicker, yet stay for much shorter periods of time. This radical change in the intensivity and tempo of work raises serious questions about the appropriateness of these sites as major loci for undergraduate teaching.

Assessment of nonarticular tenderness and prevalence of fibromyalgia in children

Fibromyalgia syndrome (FS) is most common in midlife, but may be seen at any age. Its prevalence and assessment of tenderness in healthy children is not known. We assessed 338 healthy schoolchildren for tenderness thresholds and prevalence of FS. In all children a point count of 18 tender points (TP) was conducted by thumb palpation and tenderness of some of the TP sites as well as control point sites was further assessed using a Chatillon dolorimeter. All children and their parents were questioned about the presence of widespread pain or aching. Children were considered to have FS if they met the American College of Rheumatology (ACR) criteria for diagnosis of FS. Of the 338 children, 21 (6.2%) had FS. Thresholds of tenderness of 9 TP were 5.0 (1.2) (kg) [mean (standard deviation)] for boys vs 3.6 (0.8) (kg) for girls (p < 0.001). Thresholds of tenderness of the control point sites were 7.1 (1.4) (kg) for boys vs 5.5 (1.1) (kg) for girls (p < 0.001). Thresholds of tenderness of TP and control points in the children with FS were 2.5 (0.4) (kg) and 4.2 (0.5) (kg) vs 4.5 (1.2) (kg) and 6.6 (1.4) (kg) respectively in the children without FS (p < 0.001). We suggest that FS is common in the pediatric age group. Boys have lower tenderness than girls; children with FS have lower thresholds for tenderness both at control and TP compared to the subjects without FS.

Functional coupling of neonatal rat Sertoli cells and gonocytes in coculture

Interaction between Sertoli cells and germ cells is likely to be critical for normal development of the testis. We have established and characterized cocultures of neonatal Sertoli cells and gonocytes and have begun to study the physical and functional relationship between these cells in vitro. Cells were isolated from rat pups by sequential enzymatic treatment and cultured in serum-free medium. When plated on Matrigel, Sertoli cells rapidly attach, and gonocytes adhere to the underlying Sertoli cells shortly thereafter. We observed that some of these germ cells develop cytoplasmic processes and elongate during the first day of culture, essentially mimicking their behavior in vivo. Electron microscopic examination of typical cultures revealed the presence of desmosome-like adhesion sites and apparent gap junctions between Sertoli cells and gonocytes. To determine whether Sertoli cells and gonocytes are functionally coupled in the cocultures, we used the glass bead-loading technique of McNeil and Warder to introduce Lucifer yellow (LY), a gap junction-permeant probe, and Rhodamine-dextran (RD), a larger marker excluded by gap junctions, simultaneously into cultures 24 h after plating. Immediate fixation and viewing of cultures with fluorescence microscopy indicated that all bead-loaded cells received both probes. We studied other living cultures 10 min after bead-loading and located RD-negative (i.e. nonbead-loaded) gonocytes that were in obvious contact with RD- and LY-positive bead-loaded Sertoli cells; these gonocytes were scored for the presence or absence of cytoplasmic LY. This analysis revealed that many gonocytes were able to obtain LY from adjacent Sertoli cells, presumably via gap junctions maintained with these cells. In addition, we quantified the percentage of gonocytes that elongated with increasing time in vitro and correlated the morphology of these cells with their ability to acquire LY from adjacent Sertoli cells. Our findings indicate that although the absolute numbers of gonocytes present decreases, more of those remaining elongate as time in vitro increases. We can also conclude from our data that gonocytes with and without processes are equally likely to be coupled with Sertoli cells under these conditions. These observations provide the first demonstration of functional coupling between Sertoli cells and premeiotic germ cells. Together with our morphological observations, they suggest that gap junction-mediated communication between these cells may be involved in stimulating or regulating changes in the gonocyte population during postnatal development of the testis.

Endorphin suppresses FSH-stimulated proliferation of isolated neonatal Sertoli cells by a pertussis toxin-sensitive mechanism

During perinatal development, when the size of the Sertoli cell population is determined, Leydig cells produce beta-endorphin, a peptide which may interact with Sertoli cells to modify their FSH-responsiveness, as suggested by our previous work. The goal of the present study was first, to test directly the possibility that beta-endorphin modifies the proliferative response of neonatal Sertoli cells to FSH, and second, to gain information on a mechanism(s) involved in any observed effect. We treated isolated 6-day-old Sertoli cells with FSH or vehicle in vitro and measured their incorporation of exogenous, radiolabeled thymidine with quantitative autoradiography. After 2 days in culture with FSH, we detected a 10-fold increase in the rate of Sertoli cell proliferation. The level of cell division in these FSH-treated cultures was identical to that in other cultures exposed to cAMP under similar conditions. In addition, inclusion of beta-endorphin 3 hr prior to FSH or cAMP decreased the effect of the hormone by 50% but left the cAMP response unchanged. Thus, beta-endorphin acts on isolated, neonatal Sertoli cells at a point prior to intracellular production of cAMP to suppress their response to FSH. When other cultures were treated with pertussis toxin, a blocker of intracellular GTP-binding proteins such as Gi, before sequential addition of endorphin and FSH, the effect of beta-endorphin on FSH-responsiveness was abolished. Moreover, when other cultures were exposed to pertussis toxin in the absence of endorphin, followed by FSH, their response to the hormone was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

[Assessment of diabetic autonomic neuropathy by heart rate monitoring]

Assessment of diabetic autonomic neuropathy in a representative sample of 91 noninsulin-dependent diabetics was performed in 3 community clinics. A difference of less than 10 beats/min in heart rate between deep inspiration and deep expiration determined by ECG recording served as the criterion for autonomic neuropathy. By this test, 86% of the patients had diabetic autonomic neuropathy, a slightly higher proportion than that reported by others using similar criteria in more selected populations. The test is very sensitive and can be used for screening.

Influence of prolonged submaximal exercise on the pharmacokinetics of verapamil in humans

The influence of prolonged submaximal exercise on the pharmacokinetics of verapamil was studied in normal volunteers both after i.v. injections of 0.13 mg/kg body weight as well as after one oral dose of 80 mg of the calcium entry blocker. Each dose was given on a rest day and on an exercise day. On the rest day, the terminal phase half-life (t1/2) of verapamil averaged 161 +/- 23 min after i.v. injection of the drug. The total clearance was 772 +/- 125 ml/min, and the area volume of distribution was 198 +/- 53 L. These parameters were not altered on the exercise day. Neither did exercise have any influence on the pharmacokinetic parameters determined after oral application of verapamil. This study shows that prolonged submaximal exercise has no influence on the pharmacokinetics of verapamil.

Severe multicore disease associated with reaction to anesthesia

Multicore disease is a nonprogressive myopathy. To our knowledge, in all previous cases, the clinical course has been benign with no deaths attributed to it. We describe a patient who presented as a floppy baby and remained weaker throughout his life than any other patients previously described. Biopsy findings were characteristic of multicore disease. However, at age 21/2 years, our patient developed congestive heart failure that was easily controlled with digitalis and diuretics. Shortly after cardiac catheterization, the patient developed a high, unexplained fever and died 26 hours later despite aggressive attempts at resuscitation. Therefore, patients with multicores in skeletal muscle may have severe weakness and may also have a predisposition to complications subsequent to anesthesia.

Cervical spine involvement in familial Mediterranean fever

We report a case of familial Mediterranean fever (FMF) complicated by nephrotic syndrome and renal failure due to amyloidosis. This case is unique in that the severity of joint involvement necessitated bilateral hip replacement and later caused cervical apophyseal joint fusion, the latter being a lesion not previously described in the course of FMF.

Evaluation of appropriateness and interpretation of serum theophylline assays

A drug utilization review of serum theophylline assays was undertaken to: (1) evaluate the prescribers' usage and interpretation of serum theophylline levels (STLs), and (2) calculate the cost of inappropriate assays. Criteria for appropriate use and interpretation were defined by an audit committee and approved by the chief medical resident. STLs were evaluated on medicine patients for a one-month period. Results of 102 levels ordered showed that 47 percent were inappropriate. The reasons cited most often for inappropriateness were: (1) previously-known STLs with no reason to expect a change in subsequent levels (26 percent); and (2) STLs drawn prior to steady state (12 percent). None of the levels evaluated had a request entered for the sampling time to be recorded. STLs were interpreted with the same degree of accuracy regardless of whether they were ordered appropriately. Results from this study suggest significant cost savings can be realized if physicians' ordering habits are corrected.

Ethotoin in seizures of childhood and adolescence

Ethotoin is an anticonvulsant that was considered minimally effective when introduced, but due to its apparent lack of side effects, there has been renewed interest in the drug for use in generalized and psychomotor seizures. We have characterized the pharmacokinetics of ethotoin in children and have found nonlinearity. Seizures were controlled in 16 of 17 patients, and there were no side effects reported. Gingival hyperplasia due to previous phenytoin therapy improved in all cases.

Thermal Stress Effects and Surface Cracking Associated With Laser Use on Human Teeth

A detailed study is reported of the potential thermal stress effects and surface cracking of human teeth after absorption of laser energy. This study was motivated by the desire to define damage thresholds if lasers are used for preventive dentistry techniques. A large group of extracted teeth was exposed to manually pulsed bursts of energy of varying durations from a CW CO2 laser. The teeth were examined photographically under magnification before and after irradiation, using fluorescent dye to facilitate observation of cracks in the tooth surface. In an attempt to understand the cracking phenomena, predictions of the temperatures and thermal stresses were made. The tooth surface in the vicinity of the focused beam impingement was assumed to behave as a semi-infinite solid for the short periods of time considered. Estimated stresses where cracking occurred are compared in the paper to measured values of the ultimate strength of tooth enamel. Results are shown to be in reasonable agreement with predictions. Based on this work, a criterion is given for minimizing surface damage to the tooth.