Postoperative intra-abdominal free gas after open colorectal resection

PURPOSE

An erect chest radiograph for subdiaphragmatic free gas can be a useful adjunct in detecting a defect in gastrointestinal continuity. The usefulness of this test after laparotomy has not been defined, because the period of persistence of free gas is unknown. We set out to determine the length of time for natural absorption of postlaparotomy pneumoperitoneum in a prospective cohort study.

METHOD

Plain erect chest radiographs were performed on the second and fourth postoperative day and daily thereafter until the disappearance of subdiaphragmatic free gas after laparotomy.

RESULTS

Seventy-five consecutive patients were studied after informed consent. The mean age was 62.1 (standard error of the mean, 1.7) years. On the fifth postoperative day, sixth postoperative day, and seventh postoperative day, 71.6, 80, and 89 percent of patients, respectively, had no visible subdiaphragmatic gas. Five patients had gas persisting beyond the tenth postoperative day. Two of these patients did not have an anastomosis. The use of drainage tubes did not affect significantly the mean time to disappearance of subdiaphragmatic free gas (4.5 vs. 4.9 days; P = 0.45: t-test). The duration of surgery, body mass index, and time to resume bowel function had no significant effect on gas disappearance. Two patients had a clinical leak on the fifth postoperative day. This was manifested as an increase in the collection of subdiaphragmatic gas during the course of a day.

CONCLUSION

By the sixth postoperative day 80 percent of patients had no subdiaphragmatic free gas on an erect chest radiograph regardless of the presence of a drainage tube. The erect chest radiograph may therefore be a simple and readily available adjunct in the evaluation of postoperative abdominal pain, especially after the sixth postoperative day when a similar prior examination is done routinely on the fourth postoperative day for comparison.

Donor site morbidity following vascularized fibular grafting

We examined donor site morbidity in thirty-nine patients with avascular necrosis of the femoral head treated by curettage and transplantation of a free ipsilateral fibular graft. Utilising our donor site morbidity questionnaire, scar, functional loss, wound healing, complications, and pain were analysed. Subjective complaints and objective findings were evaluated and compared. Subjective complaints were common and included a sense of instability in 42% and a sense of weakness in 37%. However, objective findings were limited. No clinical instability could be elicited and only great toe flexion (29%) and extension (43%) were found to be mildly weak. Only one patient required reoperation for a donor site problem (2%). Eighty-nine percent were pain free at time of follow-up, and 93% felt the scar was good. Range of motion of the knee and ankle of the donor site leg was not different from the nonoperated leg. Donor site morbidity for avascular necrosis of the femoral head is low.

New chiral catalysts for reduction of ketones

The condensation of o-(diphenylphosphino)benzaldehyde and various chiral diamine gives a series of diimino-diphosphine tetradentate ligands, which are reduced with excess NaBH4 in refluxing ethanol to afford the corresponding diaminodiphosphine ligands in good yield. The reactivity of these ligands toward trans-RuCl2(DMSO)4 and [Rh(COD)Cl]2 had been investigated and a number of chiral Ru(II) and Rh(I) complexes with the PNNP-type ligands were synthesized and characterized by microanalysis and IR, NMR spectroscopic methods. The chiral Ru(II) and Rh(I) complexes have proved to be excellent catalyst precursors for the asymmetric transfer hydrogenation of aromatic ketones, leading to optically active alcohols in up to 97% ee.

Anal sphincter injuries from stapling instruments introduced transanally: randomized, controlled study with endoanal ultrasound and anorectal manometry

PURPOSE

Injury sustained from the transanally introduced stapling technique was assessed by comparison with biofragmentable anastomotic ring anastomosis, which excluded anal manipulation.

METHODS

A randomized, controlled trial was conducted on consecutive patients undergoing sigmoid colectomy (where pelvic nerve injury was avoided). A bowel function questionnaire was administered six months after surgery. Anorectal manometry and endoanal ultrasonography were performed preoperatively and at six months postoperatively. The observers were blinded to the randomization.

RESULTS

There were 18 patients in the transanally introduced stapling technique group and 17 patients in the biofragmentable anastomotic ring group, with no differences in age, gender, Dukes staging, and follow-up. Three of the transanally introduced stapling technique patients had occasional liquid soiling, which was absent in biofragmentable anastomotic ring patients. Mean change in resting anal pressures was also significantly impaired when compared with patients with biofragmentable anastomotic ring (P = 0.007). Endosonographic internal sphincter fragmentation was found in five transanally introduced stapling technique patients but none after biofragmentable anastomotic ring anastomosis (P = 0.046). Internal sphincter fragmentation was associated with the impaired resting pressures (P = 0.007). External sphincter deficiencies were found after transanally introduced stapling technique in two patients (biofragmentable anastomotic ring = 0), and these were associated with the soiling (P = 0.005).

CONCLUSIONS

The transanally introduced stapling technique may result in anal sphincter defects and impaired anal pressures when assessed at six months of follow-up.

Transanal repair of rectocele corrects obstructed defecation if it is not associated with anismus

PURPOSE

Rectocele is often associated with anorectal symptoms. Various surgical techniques have been described to repair the rectocele. The surgical results are variable. This study evaluated the results of transanal repair of rectocele, with particular emphasis on the impact of concomitant anismus on postoperative functional outcome.

METHODS

Fifty-nine consecutive females who underwent transanal repair of rectocele for obstructed defecation were prospectively reviewed. All 59 patients were parous with a median parity of 2 (range, 1-6) and a median age of 58 (range, 46-68) years. The median length of follow-up was 19 (range, 6-40) months. Anismus was detected by anorectal physiology and defecography. The functional outcome was assessed by a standard questionnaire, physical examination, anorectal manometry, neurophysiology, and defecography. The quality-of-life index was obtained using a visual analog scale (from 1-10, with 10 being the best).

RESULTS

The functional outcome of transanal repair of rectocele was superior in patients without anismus. Forty (93 percent) of the 43 patients without anismus showed improved evacuation after repair compared with 6 (38 percent) of the 16 patients with anismus (P<0.05). The quality-of-life index improved (9 vs. 4) if anismus was not present (P<0.05). There were minimal complications. Hemorrhage requiring blood transfusion (2 units) occurred in one patient and urinary retention in another.

CONCLUSION

Transanal repair of rectocele is safe and, in the absence of anismus, effectively corrects obstructed defecation.

Breast cancer found at the time of breast reduction

In a recent study involving 27,500 women who had breast reduction surgery in Ontario, Canada, 17 women who were diagnosed as having breast cancer at the time of their breast reduction surgery were identified. The aims of this study were to (1) describe a population-based series of patients who had breast cancer diagnosed at the time of breast reduction, (2) describe the treatment of these cancers, and (3) compare their survival rate with survival in patients in the general population who had breast cancer. Information about these women, their treatment, and outcome was extracted from hospital records, pathology reports, and reports from regional cancer centers. The chance of finding an invasive breast cancer at the time of breast reduction was 0.06 percent, which is lower than what has been reported previously. Sixty-seven percent of these women were treated with total mastectomy. In the remaining 33 percent, who were treated with partial mastectomy, the entire tumor was removed at the time of breast reduction. Fifty percent of the women were treated with radiation, and 25 percent were treated with chemotherapy or hormonal therapy. Compared with women in the general population of Ontario who have breast cancer, women whose breast cancer is discovered during breast reduction surgery are more likely to be treated with complete mastectomy and less likely to be treated with radiotherapy or chemotherapy. Seventy-one percent of the breast reduction group were axillary node-negative at diagnosis, compared with 58 percent in the general population of women with breast cancer. Survival from breast cancer in women diagnosed at the time of breast reduction (88 percent, 5-year survival) was better than survival from breast cancer in the general population (77 percent). These findings suggest that cancers found in women at the time of breast reduction are less advanced, possibly because they are diagnosed at an earlier stage.

A follow-up study of 105 women with breast cancer following reduction mammaplasty

Reduction mammaplasty is one of the most common procedures performed by plastic surgeons in Canada. In a recent study of 27,500 women in the province of Ontario who underwent breast reduction surgery, 105 women were identified who developed breast cancer after reduction mammaplasty. The purpose of this study was to compare women who had breast cancer and had a previous breast reduction with women who had breast cancer but did not have a breast reduction. Specifically, we wanted to document patient demographics, cancer type, surgical and nonsurgical treatment, and eventual outcome. A comparison group of non-breast reduction women was taken from the cohort of breast cancer patients in the province of Ontario, and the two groups were matched for age, year of diagnosis, and place of diagnosis. It was found that (1) the average age at diagnosis of breast cancer is significantly younger for women who have had previous breast reduction surgery than for those who have not; (2) the median interval between breast reduction and cancer is 5 years; (3) the type, location, and side of breast cancers are similar in the two groups of women; (4) breast reduction does not significantly increase or decrease survival rate from breast cancer; and (5) women who have had breast reduction receive the same treatment for their breast cancer as women who have not had reduction mammaplasty.

Cecal intubation model in the rat that facilitates selective in vivo study of colonic epithelial biology: preliminary report

PURPOSE

A free-living animal model with ready and repetitive access to selected regions of the large bowel and with minimally altered bowel anatomy and physiology would facilitate the in vivo study of luminal factors on the colonic mucosa in a steady-state environment. This study describes a novel model of large-bowel intubation in the rat.

METHOD

Four Sprague-Dawley rats (240-260 g) had laparotomy and intubation of the distal colon and the cecum via a cecotomy with the use of two small tubes with restraints and transmural anchors. The tubes were tunneled and anchored to the back for infusion of fluid directly into the colon. Tube positions were studied when the animals were killed. Animals were fed on either a 10 percent fiber diet or a fiber-free diet. Stathmokinetic assessment of the distal colon was performed after one week of infusion with phosphate-buffered saline and sodium n-butyrate.

RESULTS

The technique produced an easy access without affecting the weight gain of the animals after recovery. Tube positions were accurate after three weeks at the time the animals were killed. Infusions of phosphate-buffered saline and n-butyrate were well tolerated. n-Butyrate infusions twice daily for a week reversed the atrophy in the colonic mucosa induced by dietary fiber deprivation.

CONCLUSION

An in vivo large-bowel intubation model permitting selective delivery of luminal factors provides an effective option for the study of colonic mucosal biology.

Diminutive cancers of the colon and rectum: comparison between flat and polypoid cancers

A comparative study of polypoid and flat colorectal cancers less than 20 mm in size was made. A review of the characteristics of 56 polypoid cancers and 29 flat cancers treated between April 1989 and January 1996 was performed. Both groups of cancers showed similar age and location distribution. Polypoid cancers were more likely to be well differentiated (38%) than were flat cancers (17%) (P < 0.05). Flat cancers were more likely to have reached the serosa (52% vs 12%; P < 0.01) and also demonstrated a higher frequency of lymph node involvement (41% vs p 9%) (P < 0.01) when compared to polypoid cancers. Flat colorectal cancers belong to a distinct subset which demonstrates greater biological aggressiveness than polypoid cancers of equivalent size.

The Colorectal Cancer Recurrence Support (CARES) System

Colorectal cancer has risen in incidence to become the second commonest form of cancer in Singapore. The primary treatment is surgery but up to 50% of patients still suffer from recurrence of the cancer after surgery. Early identification of recurrence will increase the effectiveness of therapy and the survival of patients. This paper describes the CARES (Cancer Recurrence Support) System, whose objective is to predict the recurrence of colorectal cancer, using Case-based Reasoning (CBR), and supported by other techniques such as data mining and natural language processing. The CARES System employs CBR to compare and contrast between the new and past colorectal cancer patient cases, and makes inferences based on those comparisons to determine the high risk patient groups. The features and functionality of the system are described.

Broadly tunable mid-infrared femtosecond optical parametric oscillator using all-solid-state-pumped periodically poled lithium niobate

We describe a high-repetition-rate femtosecond optical parametric oscillator (OPO) that was broadly tunable in the mid infrared. The all-solid-state-pumped OPO was based on quasi-phase matching in periodically poled lithium niobate. The idler was tunable from approximately 1.7 mum to beyond 5.4 mum, with maximum average power levels greater than 200 mW and more than 20 mW of average power at 5.4 mum. We used interferometric autocorrelation to characterize the mid-infrared idler pulses, which typically had durations of 125 fs. This OPO had a pumping threshold as low as 65 mW of average pump power, a maximum conversion efficiency of >35% into the near-infrared signal, a slope efficiency for the signal of approximately 60%, and a maximum pump depletion of more than 85%.

Prospective randomized trial of drainage alone vs. drainage and fistulotomy for acute perianal abscesses with proven internal opening

PURPOSE

Incision and drainage (I & D) with concurrent or delayed fistulotomy is the usual treatment for abscess-fistula with a demonstrated internal opening. We compared incision and drainage alone vs. with concurrent fistulotomy for perianal abscesses with a demonstrated internal opening.

METHODS

Consecutive patients with acute perianal abscesses and a demonstrated internal opening were prospectively randomized into either the I & D group or drainage with concurrent fistulotomy group. They were followed up at one month, three months, and one year.

RESULTS

The I & D group had 21 patients, and the fistulotomy group had 24 patients. Thirteen patients had low intersphincteric abscess-fistula, and seven had low transsphincteric fistulas in the I & D group. The fistulotomy group had 9 intersphincteric abscess-fistula compared with 14 low transsphincteric ones. Median duration of surgery, hospital stay, and continence at final follow-up were the same in the two groups. Three had recurrent abscess-fistula in the I & D group compared with none in the fistulotomy group (P = 0.09).

CONCLUSION

I & D alone for acute anal abscess-fistula with demonstrated internal opening showed a tendency to recurrence that did not reach a statistically significant difference compared with concurrent fistulotomy. I & D, therefore, puts only a few patients at risk for recurrence.

Ileostomy output in the early postoperative period

The high volume output of a defunctioning loop ileostomy after rectal excision and anastomosis may lead to severe dehydration and electrolyte imbalance if not properly managed. Although chronic losses may be seen, the early postoperative period remains the most hazardous with regard to acute fluid and electrolyte losses for the patient with a defunctioning ileostomy1–3. A prospective study was therefore conducted to determine the period and severity of excessive ileostomy loss.

High-repetition-rate femtosecond optical parametric oscillator based on KNbO(3)

A Ti:sapphire-pumped, high-repetition-rate, femtosecond optical parametric oscillator based on potassium niobate is described. Signal pulses as short as 90 fs have been recorded, and idler pulses as short as 105 fs have been measured. Tuning from 1.2 to 1.4 microm in the signal branch and from 1.76 to 2.2 microm in the idler branch has been achieved. Output powers as high as 300 mW have been measured at the signal wavelength.

High-repetition-rate femtosecond optical parametric oscillator based on RbTiOAsO(4)

A high-repetition-rate Ti:sapphire-pumped femtosecond optical parametric oscillator based on the new nonlinear-optical crystal RbTiOAsO(4) is described. Tuning from 1.03 to 1.3 microm in the signal branch and from 2.15 to 3.65 microm in the idler branch with powers as high as 250 mW in the signal and 200 mW in the idler is presented. The possibility of extending the tuning range beyond 3.65 microm is discussed.

Operative treatment of acetabular fractures

A retrospective review of 23 patients with acetabular fractures operated upon between January 1985 and December 1990 was conducted. Eighteen patients were available for assessment of functional outcome. Radiological results were also evaluated. The majority of the patients were male and the average age was 35 years. Three-quarters of the patients had an injury to another system. Three-quarters of the patients were operated upon within two weeks and only two patients had complications directly related to the operation. Radiological result was excellent or good in 61%, fair in 22%, and poor in 16% of the patients. Functional score was excellent or good in 72%, fair in 16% and poor in 11%. In summary, operative treatment of acetabular fracture is a safe and acceptable method of managing displaced acetabular fractures.

Thermal lens spectrometry using a broadly tunable optical parametric oscillator

We present a computerized optical parametric oscillator that is capable of continuous tuning from approximately 420 nm to 2 µm for spectroscopic and spectrometric applications. This system allows any selected wavelength within the tuning range to be reached directly and quickly. We demonstrate the versatility of the system by measuring the entire visible (450-690-nm) thermal lens spectrum of NO(2) with a continuous scan.

High-repetition-rate femtosecond optical parametric oscillator based on CsTiOAsO(4)

A high-repetition-rate Ti:sapphire-pumped optical parametric oscillator based on the new nonlinear optical crystal CsTiOAsO(4) is described. The operation of this optical parametric oscillator is characterized for a 90 degrees -cut crystal by use of a type II interaction. Tuning from 1.46 to 1.74 microm is demonstrated, and there is the potential for tuning from 0.9 to 5 microm with angle tuning. Powers of 100 mW in the signal and the idler branches are obtained. Pulse widths as short as 64 fs are generated with and without prisms in the cavity.

High-power, high-repetition-rate femtosecond pulses tunable in the visible

We demonstrate a Ti:sapphire-pumped intracavity-doubled optical parametric oscillator (OPO) that generates a total of up to 240 mW of sub-100-fs pulses tunable in the visible. The OPO consists of a 1.5-mm-thick KTiPO(4) (KTP) crystal configured in a ring cavity that is synchronously pumped by a self-mode-locked Ti:sapphire laser operating at an 81-MHz repetition rate and 2.1-W average power, producing 115-fs pulses at lambda = 790 nm. Intracavity doubling of the OPO is accomplished by inserting a 47-microm-thick beta-BaB(2)O(4) crystal into an additional focus in the OPO cavity. We demonstrate continuous tuning of the second-harmonic output from 580 to 657 nm. The potential tuning range of this intracavity-doubled KTP OPO is approximately 500 to 800 nm.

Self-starting mode-locked ring-cavity Ti:sapphire laser

A self-mode-locked ring-cavity Ti:sapphire laser is described that is self-starting within milliseconds and completely unperturbed by the self-starting mechanism while mode locked. This technique makes use of a position-modulated mirror in an external cavity in which the cavity length and alignment are noncritical. Other benefits of the ring cavity over the linear cavity configuration are described.

Ti:sapphire-pumped, high-repetition-rate femtosecond optical parametric oscillator

A broadly tunable femtosecond optical parametric oscillator (OPO) based on KTiOPO(4) that is externally pumped by a self-mode-locked Ti:sapphire laser is described. Continuous tuning is demonstrated from 1.22 to 1.37 microm in the signal branch and from 1.82 to 2.15 microm in the idler branch by using one set of OPO optics. The potential tuning range of the OPO is from 1.0 to 2.75 microm and requires three sets of mirrors and two crystals. Without prisms in the OPO cavity, 340 mW (475 mW) of chirped-pulse power is generated in the signal (idler) branch for 2.5 W of pump power. The total conversion efficiency as measured by the pump depletion is 55%. With prisms in the cavity, pulses of 135 fs are generated, which can be shortened to 75 fs by increasing the output coupling.

Analysis of one hundred and twenty five patients with primary liver cancer surviving more than five years

During the period of 1958-1986, a series of 125 patients with pathologically proven hepatocellular carcinoma (HCC) surviving more than 5 years was collected in authors' institute. Thirty seven of them survived more than 10 years, the longest being 30 years. Of the entire series, 55.2% of patients was discovered by screening, 48.0% of patients was subclinical HCC, 80.0% of patients had solitary tumor, and 53.6% of patients had tumor size smaller than 5 cm. Pathological findings revealed that 90.2% of tumor was grade I and II (Edmondson grading) and 81.6% of patients associated with cirrhosis. The serum HBsAg was positive in 63% and anti-HBc in 80% of the patients who had checked the HBV markers. Of the 125 patients, 108 patients received resection, 67 patients were small HCC resection, 41 patients were non-small HCC resection, re-resection for subclinical recurrence or solitary lung metastasis was done in 26 patients with resection. Limited resection amounted to 54.6% of patients with resection. Of the 125 patients, 17 patients received palliative surgery other than resection, including hepatic artery ligation, cannulation, or their combination, etc. Eight out of the 17 patients received second stage resection due to marked shrinkage of tumor. It is concluded that early resection remained the major approach to get a long-term survivor, re-resection for subclinical recurrence is also of proved merit. Resection of huge tumor is still useful but less effective. Cyto-reduction and sequential resection is a new trend. Primary liver cancer (PLC) has long been recognized as incurable malignancy with extremely low 5-year survival rate. According to the cancer statistics in the United States, the relative 5-year survival rates for patients with PLC was 2% in 1960-1963, 3% in 1970-1973, 4% in 1974-1976, 3% in 1977-1980 and 5% in 1981-1986. Patients with PLC survived more than 5 years were rarely reported in the literature. In 1971, Curutchet collected worldwide data from 45 authors covering the period for 65 years (1905-1970), only 45 patients with PLC were found to be 5-year survivors. Thanks to the progress in tumor markers, particularly alpha fetoprotin (AFP) and new localization measurements, diagnosis and treatment are possible in subclinical stage. Based on combined strategies to the treatment of PLC including resection of small liver cancer, re-resection of subclinical recurrence after curative resection, multimodality treatment, and sequential resection after shrinkage of tumor, the 5-year survival of PLC has gradually increased.(ABSTRACT TRUNCATED AT 400 WORDS)

Substrate preparation for reliable imaging of DNA molecules with the scanning force microscope

A simple method of substrate preparation for imaging circular DNA molecules with the scanning force microscope (SFM) is presented. These biomolecules are adsorbed onto mica that has been soaked in magnesium acetate, sonicated and glow-discharged. The stylus-sample forces that may be endured before sample damage occurs depends on the ambient relative humidity. Images of circular DNA molecules have been obtained routinely using tips specially modified by an electron beam with a radius of curvature, Rc, of about 10 nm [D. Keller and C. Chih-Chung, Surf. Sci. 268 (1992) 333]. The resolution of these adsorbed biomolecules is determined by the Rc. At higher forces individual circular DNA molecules can be manipulated with the SFM stylus. Strategies to develop still sharper probes will be discussed.

Circular DNA molecules imaged in air by scanning force microscopy

Routine and reproducible imaging of DNA molecules in air with the scanning force microscope (SFM) has been accomplished. Circular molecules of plasmid DNA were deposited onto red mica and imaged under various relative humidities. In related experiments, the first images of the Escherichia coli RNA polymerase-DNA complex have also been obtained. This has been possible by (1) the use of specially modified SFM tips with a consistent radius of curvature of 10 nm or less, to minimize the amount of image distortion introduced by the finite dimensions of commercially available tips, (2) the optimization of a method to deposit and bind DNA molecules to the mica surface in a stable fashion, and (3) careful control of the sample humidity, to prevent solvation of the molecules and detachment from the surface by the scanning tip or stylus. Contact forces in the range of a few nanonewtons are routinely possible in air and in the presence of residual humidity. The spatial resolution of the images appears determined by the radius of curvature of the modified styli, which can be estimated directly from the apparent widths of the DNA molecules in the images.

Effect of a purified somatostatin monoclonal antibody and its Fab fragments on gastrin release

The effect of a purified somatostatin monoclonal antibody, SOMA 10, and its Fab fragments on gastrin release have been examined in the isolated perfused rat stomach. SOMA 10 was purified from ascites fluid by ammonium sulfate precipitation followed by hydroxylapatite (HAP) chromatography. This gave a preparation of greater than 90% purity, as assessed by fast affinity and size exclusion high-performance liquid chromatography (HPLC). HAP-purified SOMA 10 had a binding capacity of 760 mmol somatostatin/mol antibody, a dissociation constant of 2.2 nM, and recognized amino acid residues 5-12 of the somatostatin molecule. Fab fragments of SOMA 10 were prepared and purified by protein A affinity chromatography, and the purity assessed by HPLC and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Single passage perfusion of SOMA 10 (100 micrograms/ml) into the gastric vasculature caused a paradoxical decrease in basal gastrin release. However, recirculation of the antibody (20 micrograms/ml) caused an increase in cumulated gastrin release. Perfusion of Fab fragments of SOMA 10 (66 micrograms/ml) also increased gastrin secretion. These results support the suggestion that somatostatin exerts a tonic restraint on gastrin release and that penetration of the antibody to the site of somatostatin release is necessary for it to have an effect.

Requirement for solutions with oncotic pressure to release ANF during blood volume expansion in conscious and anesthetized rats

We examined the effect of a 30% blood volume expansion with either blood, isotonic saline, or isotonic saline plus albumin on the release of immunoreactive-atrial natriuretic factor (IR-ANF) in conscious and barbiturate-anesthetized rats. Immediately prior to volume expansion, resting plasma IR-ANF levels were significantly (p less than 0.05) higher in the conscious animals (61 +/- 5 pg/mL, n = 19) compared to the anesthetized animals (41 +/- 3 pg/mL, n = 19). Volume expansion with blood from donor rats significantly (p less than 0.05) elevated IR-ANF in both groups, but the increase in the conscious rats (+492 +/- 32 pg/mL, n = 6) was significantly (p less than 0.05) greater than that of the anesthetized rats (74 +/- 25 pg/mL, n = 6). Similarly, volume expansion with isotonic saline containing 38 mg/mL albumin significantly (p less than 0.05) elevated IR-ANF levels in both groups, but the increase in the conscious group (379 +/- 102 pg/mL, n = 7) was significantly (p less than 0.05) greater than that of the anesthetized group (94 +/- 32 pg/mL, n = 7). These elevations in IR-ANF levels were not significantly different between either of the conscious groups or either of the anesthetized groups. Volume expansion with isotonic saline alone did not have any significant effect upon resting IR-ANF levels in either conscious (+8 +/- 14 pg/mL, n = 6) or anesthetized (-7 +/- 6 pg/mL, n = 6) animals. From these results, it would appear that a) isotonic saline alone does not stimulate IR-ANF release when used to expand blood volume, and b) barbiturate anesthesia significantly lowers resting plasma IR-ANF levels and attenuates the release of IR-ANF in response to volume expansion.

Long-term survivors after resection for primary liver cancer. Clinical analysis of 19 patients surviving more than ten years

From July 1958 to June 1978, a total of 333 cases with pathologically proven primary liver cancer (PLC) were admitted to the Zhong Shan Hospital, Shanghai Medical University, Shanghai, the people's Republic of China. Of these, 39.6% (132 of 333) were resected and 14.4% (19 of 132) survived over 10 years after resection for PLC. These 19 patients surviving over 10 years were investigated in this paper. All 19 patients underwent radical resection, including right hemihepatectomy in two cases, left hemihepatectomy in ten cases, left lateral segmentectomy in three cases, and local resection in four cases. By the end of June 1988, follow-up varied from 10 years and 1 month to 26 years and 7 months, with a mean follow-up of 15 years and 4 months. All 19 patients are still alive with free of disease. The longest survival patient had a tumor measuring 10 X 8 X 6 cm in size and underwent local resection. Upon follow-up after 26 years and 7 months, the patient was found to be still living and well. Two patients with intraperitoneal ruptured PLC have survived for 19 years and 4 months, and 16 years and 11 months, respectively, after resection of the tumors free of disease and have returned to work. Subclinical recurrence of PLC was discovered in one patient in whom reoperation with cryosurgery was carried out. The patient has been in good condition with negative alpha-fetoprotein (AFP) for 8 years and 10 months after cryosurgery. Subclinical solitary pulmonary metastasis was detected in two patients because of a secondary rise in AFP level. Reoperations were carried out and the metastatic tumors were removed. These two patients are still in good health with negative AFP 9 years and 6 months, and 10 years and 1 months, respectively, after reoperation. These results indicate that early and radical resection are the principal factors influencing long-term survival; reoperation for subclinical recurrence and solitary metastasis remains an important approach to prolong survival further; intraperitoneal rupture of PLC does not exclude the possibility of cure; new surgical techniques, such as cryosurgery and bloodless hepatectomy, have been shown to be effective in some patients.

Research on nonlinear optical materials: an assessment

The seven papers making up this assessment are based on the Workshop on Nonlinear Optical Materials held in April 1986.

Dynamic interferometry techniques for optical path length measurements

Two dynamic interferometric techniques based on electrically tunable lasers are described and experimentally demonstrated. The first technique allows for measurements of small phase modulations in interferometers independently of dc drifts and low frequency noise in the interferometer. The second scheme is a true FM technique suited for continuous real-time noncontact measurements of the optical thickness of transparent materials.

High-sensitivity laser wavelength-modulation spectroscopy

The method of doing dual-beam single-detector wavelength-modulation spectroscopy originally proposed by Bonfiglioli and Trench is demonstrated experimentally, using a tunable laser. This system monitors both the reference and the sample beams continuously in phase quadrature and measures the derivative and the direct spectra simultaneously. When this system was used in conjunction with an electro-optically tuned cw dye laser, a sensitivity of (1/T) (dT/dlambda) = 3 x 10(-6) A(-1) was experimentally achieved for modulation depths from 1 to 50 A and can be extended down to 0.1 A. The derivative spectrum corresponding to the extremely weak fifth overtone of the C-H stretching vibration in the electronic ground state of benzene has been observed in a path length as short as 1 cm.

Reduction of alpha-oxo carboxylic acids by pigeon liver 'malic' enzyme

1. Pigeon liver ;malic' enzyme [l-malate-NADP(+) oxidoreductase (decarboxylating); EC 1.1.1.40] was shown to catalyse the reductase reaction: [Formula: see text] l-Malate was identified as the reaction product, and was formed in stoicheiometric amount. 2. In addition to oxaloacetate and pyruvate, a number of other alpha-oxo carboxylic acids were also reduced.