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Biomedical subjects

U Neff

Publications and source records attributed to U Neff.

At least 19 recordsLinked to original sources
PubMed2001

Strong coherence between solar variability and the monsoon in Oman between 9 and 6 kyr ago.

Variations in the amount of solar radiation reaching the Earth are thought to influence climate, but the extent of this influence on timescales of millennia to decades is unclear. A number of climate records show correlations between solar cycles and climate, but the absolute changes in solar intensity over the range of decades to millennia are small and the influence of solar flux on climate is not well established. The formation of stalagmites in northern Oman has recorded past northward shifts of the intertropical convergence zone, whose northward migration stops near the southern shoreline of Arabia in the present climate. Here we present a high-resolution record of oxygen isotope variations, for the period from 9.6 to 6.1 kyr before present, in a Th-U-dated stalagmite from Oman. The delta18O record from the stalagmite, which serves as a proxy for variations in the tropical circulation and monsoon rainfall, allows us to make a direct comparison of the delta18O record with the Delta14C record from tree rings, which largely reflects changes in solar activity. The excellent correlation between the two records suggests that one of the primary controls on centennial- to decadal-scale changes in tropical rainfall and monsoon intensity during this time are variations in solar radiation.

Journal Article↗
PubMed1998

Laminar and arch fractures with dural tear and nerve root entrapment in patients operated upon for thoracic and lumbar spine injuries.

OBJECTIVE: To determine the neurological outcome in patients with laminar fractures associated with dural tears and nerve root entrapment, operated upon for thoracic and lumbar spine injuries. PATIENT POPULATION: Out of 103 patients operated upon consecutively for thoracic and lumbar spine injuries during the period 1990 to 1994 inclusive, 24 (23.3%) patients had laminar fractures out of whom 3 (2.9%) had an associated dural tear and an other 17 (16.5% or 70.8% of the total patients with laminar fractures) had an associated dural tear and nerve root entrapment. RESULTS: Twelve (70.5%) patients had injury at the thoraculumbar junction, 13 (76.5%) had Magerl's type A3 or above, 10 (58.8%) had a kyphotic angle deformity greater than 5 degrees. Seven (41.1%) had their spinal canal's sagittal diameter reduced by at least 50% and two had dislocations. Nine (52.9%) had initial neurological deficits. Four (50%) out of 8 patients with no initial neurological deficits (Frankel E) worsened to Frankel D. However, one patient among the 3 with initial Frankel A improved to Frankel C while both patients with initial Frankel C usefully improved to final Frankel grades D and E respectively. Two of the four patients with initial Frankel D improved to Frankel E, the other 2 remaining unchanged. All in all five patients neurological status improved, 4 worsened and 8 remained unchanged after neurosurgical treatment. CONCLUSIONS: Vertical laminar fractures with dural tears and nerve root entrapment represent a special group of thoracic and lumbar spine injuries that carry a poor prognosis. However, special operative precautions lead to significant improvement in some of them although a majority remain unchanged or even worsened.

Adult↗
PubMed1997

[Intestinal foreign body with sigmoid perforation in an area of carcinomatous stenosis: incidental finding or etiology?].

Ingestion of a foreign body is a common incident. In most cases it rarely produces symptoms, but sometimes may cause severe complications such as abscess formation, obstruction or perforation. A definite diagnosis can be difficult to obtain for the following reasons: 1. the past history doesn't give any clue; 2. the symptoms are veiled by another intestinal disease; 3. radio opaquity of the foreign body is absent; 4. complications can mimic different symptoms inspite of their unique etiology. The following case reports a patient with an intestinal perforation, where a foreign body and a stenosis, caused by a sigma neoplasm, were simultaneously present. Histological findings showed that the foreign body, not the neoplasm, was causing the perforation, whereas for the underlying disease it only was an incidental finding.

Adenocarcinoma↗
PubMed1996

Neurosurgical management of thoracic and lumbar vertebral osteomyelitis and discitis in adults: a review of 43 consecutive surgically treated patients.

We report 43 consecutive surgically treated patients with pyogenic (37 patients) and tuberculous (6 patients) osteomyelitis of the thoracic and lumbar spine encountered within an 8-year period, including 1 with late recurrence after 15 months. There were 24 men and 18 women, ranging in age from 21 to 83 years. Twenty-six patients were in poor general condition because of associated illnesses, especially diabetes mellitus. Disease occurred at the thoracic level in 19 patients and on the lumbar spine in 24. After diagnosis, five patients were merely treated by posterior decompression; three of them, however, required further surgery for recurrent infection, spinal instability, and secondary neurological impairment. They are included in the 40 patients who underwent combined posterior débridement and internal fixation with transpedicular screw-rod systems. Autologous interbody bone grafting was performed simultaneously in 18 patients and in a second stage operation in 21 patients. One of them (tuberculous) experienced early recurrence and required anterior fusion. In two patients, methylmethacrylate packing was used for spine reconstruction; one of them had a late recurrence. Of the 26 patients with preoperative marked or severe neurological deficit (Frankel Grades A, 2 patients; B, 1 patient; C, 17 patients; and D, 6 patients), 23 (88%) had significant improvement of one grade (15 patients) or more (8 patients). There were no permanent complications. However, intensive care treatment was necessary in 20 of the 26 patients in reduced general condition (mean age, 72 yr). Two patients required further surgery because of postoperative epidural hematoma and pedicle screw malpositioning. In conclusion, most patients with thoracic and lumbar osteomyelitis can be successfully treated by combined débridement and internal fixation using only a posterior approach. Autogenous interbody bone grafting can be simultaneously performed and allows early mobilization of the patient.

Adult↗
PubMed1996

[Choledochus carcinoma in choledochal cyst--a rarity. Presentation of the disease with a case report].

Around 1800 choledochal cysts are described in the literature, of which around 6% have turned malignant. The incidence of malignant degeneration increases with age and amounts to as much as 28%. As the prognosis for malignant choledochal cysts is poor, the only therapy is an early cystectomy before the appearance of malignant changes. The diagnosis of the cyst is made using sonography, ERCP and abdominal CT. Histology alone provides conclusive diagnosis of malignant degeneration. The case of a 29-year-old-woman who entered our clinic with non-specific right-side abdominal pains is presented. A choledochal cyst was diagnosed by means of sonography, ERCP and abdominal CT. Intraoperatively, a choledochal carcinoma was found in the choledochal cyst (type Ia according to Todani), with infiltration to the surrounding area as well as liver metastasis. A cystectomy and Roux-Y-hepatico-jejunostomy were performed. The patient died 8 months after the diagnosis.

Adult↗
PubMed1996

[Subcapital humerus fracture with lesion of the axillary artery. 2 case reports and review of the literature].

Two cases of fractures of the humeral neck in association with an axillary artery injury are reported. Even now, there are still only 14 well-documented cases in the literature. Trauma, pattern of injuries and treatment are analyzed. The treatment is focused on preservation of hand function, which is more important than shoulder motion. Neurovascular damage causes an impairment of hand function. The priorities of treatment (reperfusion versus osteosynthesis) are dictated by the degree of ischemia. Long-term disability is determined by brachial plexus injury.

Aged↗
PubMed1994

Operative treatment of distal humeral fractures in the elderly.

We treated 49 patients at an average age of 80 years (75 to 90) with distal mostly intraarticular humeral fractures by open reduction. There were 8 class A, 13 class B and 28 class C fractures on Müller's classification. The patients were reviewed at a postoperative average of 18 months. The patients' assessment of the result was very good in 31%, good in 49%, fair in 15% and poor in 5%. The flexion-extension range was very good in 41%, good in 44% and fair in 15%. The incidence of implant failure, pseudarthrosis of the olecranon osteotomy and ulnar nerve lesion was no higher in these elderly patients than in younger patients. Old age is not a contraindication to open reduction and internal fixation; it is important to restore full function.

Age Factors↗
PubMed1993

Antibiotic prophylaxis with two doses of cephalosporin in patients managed with internal fixation for a fracture of the hip.

A prospective, randomized, double-blind study was performed to evaluate the effects of antibiotic prophylaxis on the development of a wound infection in 239 patients who had immediate stabilization of a fracture of the proximal part of the femur with a dynamic hip screw. The effects of two perioperative doses of cefotiam, given twelve hours apart, were compared with those of two doses of a placebo. Sixteen perioperative risk factors were evaluated to determine whether it was possible to identify patients who were at risk for a wound infection. All patients were followed for a minimum of six weeks. Antibiotic prophylaxis significantly reduced the prevalence of wound infection (p < 0.05): the rate of major wound infection decreased from 5 to 1 per cent and the rate of minor wound infection, from 11 to 4 per cent. The most powerful predictors of major wound infection were the duration of the operation, the interval between the accident and admission to the hospital, and the duration of postoperative urinary catheterization. The preoperative level of serum albumin and the absolute lymphocyte count were significant predictors (p < 0.05) of minor wound infection and systemic infection, respectively.

Aged↗
PubMed1993

[Distal humerus fractures in patients over 75 years of age. Long-term results of osteosynthesis].

The aim of this retrospective analysis was to evaluate the adequacy of internal fixation of distal humerus fractures in patients over 75 years of age. 49 patients were evaluated. The mean age was 80 (75-93) years. The fractures were classified as 28 C-, 13 B- and 8 A-types according to the AO-system. Primary stable fixation was followed by early assisted mobilisation. The mean average follow-up time was 18 months. Excellent and good functional results were observed in 85%. 66% of all patients have no pain. There were 6 sensible ulnar nerve lesions, one deep wound infection, one pseudarthrosis of the distal humerus and one non union of the olecranon osteotomy. We conclude from our results that open reduction and internal fixation is indicated also for patients over 75 years with distal intraarticular humeral fractures.

Aged↗
PubMed1992

[Dangerous hypoprothrombinemic hemorrhage in antibiotic therapy].

Antibiotics can be associated with hypoprothrombinaemic haemorrhages in risk patients. Risk factors are: poor nutrition, impaired liver- or renal function, coagulation depleting medical therapy or illness. Pathogenetically there is a vitamin K deficiency with reduction of vitamin K dependent clotting factors; mainly by decreased vitamin K synthesis in intestinal bacterias. In consequence every risk patient under antibiotics should receive vitamin K prophylactically and in a parenteral way, because of unreliable resorption in gastrointestinal tract. Prothrombin-time-monitoring is essential to recognize the hypoprothrombinemia in every risk patient under antibiotics.

Aged↗
PubMed1991

[Diagnostic significance of clinical symptoms versus ultrasonography in appendicitis. A prospective study].

The aim of the presented study was to find what importance ultrasonography has in the diagnosis of acute appendicitis compared to clinical findings and on the surgeon's decision regarding to laparotomy. 111 patients entering the emergency station with suspected appendicitis were evaluated in a prospective clinical study. Surgeon and radiologist had to commit themselves to the diagnosis, afterwards signs were discussed. Clinical accuracy over all was 89%. Pain migration and peritonitis signs corresponded significantly with appendicitis (p less than 0.0001). The appendix was well seen in sonographic examination in 32% (accuracy 80%), in 27% was doubtful (accuracy 70%), and in 41% the appendix could not be demonstrated. Diameter of a normal appendix was 8 mm compared to 12 mm for an inflamed appendix (p less than 0.05). Rates negative laparotomies decreased from 16% to 12.7%. The surgeon was not influenced by sonography in 75%. In 12% ultrasonography decided for laparotomy and in 4.5% sonography prevented operation. We conclude from our results, that sonography reduces the negative laparotomy rate. Ultrasonography is especially useful in doubtful clinical pictures. Clinical findings and experience remain of major importance in appendicitis-diagnosis.

Adolescent↗
PubMed1991

[Does sonography help in the diagnosis of appendicitis?].

The aim of the presented study was to find whether improvement has ultrasonography in the diagnosis of acute appendicitis and on surgeon's decision referring to laparotomy. 111 patients entering into the emergency station with suspected appendicitis were evaluated in a prospective clinical study. Surgeon and radiologist had to commit themselves to the diagnosis, afterwards signs were discussed. In 32% the appendix was well seen (accuracy 80%), in 27% sonographic examination was doubtful (accuracy 70%) and in 41% the appendix could not be demonstrated. Diameter of normal appendix was 8 mm compared to inflamed appendix with 12 mm (p less than 0.05). The negative laparotomy decreased from 16% to 12.7%. Surgeon was not influenced by sonography in 75%. In 12% ultrasonography decided for laparotomy and in 4.5% sonography prevented operation. We conclude from our results, that sonography reduces negative laparotomy rate. Especially ultrasonography is useful in doubtful clinical pictures.

Abdomen, Acute↗
PubMed1989

[Successful treatment of a cheilothorax in lymphangiomatosis of the ribs (Gorham-Stout syndrome)].

In 1955 Gorham and Stout described the syndrome of lymphangiomatosis of the bone resulting in widespread monofocal osteolysis in the skeletal system. The results of therapy are difficult to evaluate as the disease may come to a sudden stand-still. If angiomatosis arises near the thorax, pleural effusion occurs due to simultaneous involution of the thoracic duct. This complication has a fatal outcome and effective treatment is required. A case is reported in a 61-year-old male in whom radiotherapy of the lower ribs on the right thorax reduced the lymphangiomatous swelling and healed the chylothorax.

Bone Neoplasms↗
PubMed1989

[Antibiotic prophylaxis in colon surgery: cefazolin (Kefzol- ornidazole (Tiberal) versus cephazolin-placebo].

A prospective, randomized, double-blind and controlled clinical trial of systemic antibiotic prophylaxis with Cefazolin and Ornidazol (CO) versus Cefazolin and Placebo (CP) was carried out consecutively in 100 patients undergoing elective, colorectal surgery. The incidence of wound infection in the CP-group was 20% (n = 10) and in the CO-group 8% (n = 4) (p less than 0.10 ns). The reduction of anaerobic bacterias from 20% (n = 10) in the CP-group to 0% (n = 0) (CO) was significant (a1 = 0.0139; a2 = 0.0277 s, Fischer's exact test). The time of hospitalization was reduced from 20.3 days (CP) to 16.7 days (CO) (p less than 0.05 s). The agent for antibiotic prophylaxis in elective colorectal surgery is to cover the spectrum of anaerobic bacterias.

Adolescent↗
PubMed1989

[Preoperative assessment of at-risk patients in traumatology].

In a randomized, prospective double blind trial evaluating antibiotic prophylaxis for internal fixation of proximal femur fractures, the prognostic value of preoperative risk parameters, namely triceps skinfold, upper arm circumference, dynamometry, serum albumin, transferrin, prealbumin, lymphocyte count and serum zinc was analyzed. A population at risk of postoperative infection could be defined with serum albumin value and lymphocyte count: a serum albumin of less than 40 g/l correlated with increased local complications and a lymphocyte count under 1400 microliters coincided with increase in systemic infections. No correlation between perioperative transfusion and postoperative infections was found.

Aged↗
PubMed1988

Unicondylar fractures of the distal humerus: an operative approach.

This paper retrospectively reviews a series of 22 unicondylar fractures of the distal end of the humerus that were treated by open reduction and internal fixation over a 10 year period. The fracture patterns were classified according to the system of Müller et al. A strict rating scale was developed that incorporated subjective data, objective elbow motion, and the functional status of the involved elbow. At an average follow-up of 5.9 years (range 2.3 to 12.3 years), 12 elbows were rated as excellent, 6 as good, and 4 as fair. Complications included extensive posttraumatic arthritis in four patients, a nonunion in one, and a transient radial nerve palsy in one.

Adolescent↗