A versatile Raman setup with time-gating and fast wide-field imaging capabilities

Raman spectroscopy is a well-established method for chemical identification, with a wide variety of applications. The two major limitations are that fluorescence can hamper detection, and that Raman imaging is slow; it typically takes multiple hours to measure even a small surface area. We have developed a multimodal setup that mitigates these limitations. The setup has a point-scanning mode that allows for time-gated as well as continuous Raman spectroscopy, and both modes use an 80 MHz, 532 nm excitation laser with up to 20 W of power. The fluorescence suppression capabilities of the setup were demonstrated by comparing time-gated to continuous detection of a Dracaena leaf. Raman bands showed a 4-8 times improvement in signal-to-background ratio, and one band that was invisible in the continuous measurement, became visible in the time-gated measurement. The setup also has a 4-band simultaneously detected wide-field mode. Using a set of beam splitters, the Raman signal from the sample is split. This signal is imaged onto four separate cameras, each with a specific band-pass filter. The wide-field data were processed using principal component analysis with k-means clustering. To illustrate the wide-field capabilities of the setup, a 1mm2 sample containing aspirin, caffeine and paracetamol was measured using 10 W excitation power. A 10-second measurement enabled identification of the compounds, and a 1-second measurement showed promising results. This brings the setup close to real-time imaging, showing great potential for applications in quality control or for measuring samples that change over time.

Baker Grade IV Capsular Contracture Is Correlated with an Increased Amount of Silicone Material: An Intrapatient Study

BACKGROUND

Breast implant surgery is one of the most frequently performed procedures by plastic surgeons worldwide. However, the relationship between silicone leakage and the most common complication, capsular contracture, is far from understood. This study aimed to compare Baker grade I with Baker grade IV capsules regarding their silicone content in an intradonor setting, using two previously validated imaging techniques.

METHODS

Twenty-two donor-matched capsules from 11 patients experiencing unilateral complaints were included after bilateral explantation surgery. All capsules were examined using both stimulated Raman scattering (SRS) imaging and staining with modified oil red O (MORO). Evaluation was done visually for qualitative and semiquantitative assessment and automated for quantitative analysis.

RESULTS

Using both SRS and MORO techniques, silicone was found in more Baker grade IV capsules (eight of 11 and 11 of 11, respectively) than in Baker grade I capsules (three of 11 and five of 11, respectively). Baker grade IV capsules also showed significantly more silicone content compared with the Baker grade I capsules. This was true for semiquantitative assessment for both SRS and MORO techniques ( P = 0.019 and P = 0.006, respectively), whereas quantitative analysis proved to be significant for MORO alone ( P = 0.026 versus P = 0.248 for SRS, respectively).

CONCLUSIONS

In this study, a significant correlation between capsule silicone content and capsular contracture is shown. An extensive and continued foreign body response to silicone particles is likely to be responsible. Considering the widespread use of silicone breast implants, these results affect many women worldwide and warrant a more focused research effort.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

Label-free stimulated Raman scattering imaging reveals silicone breast implant material in tissue

Millions of women worldwide have silicone breast implants. It has been reported that implant failure occurs in approximately a tenth of patients within 10 years, and the consequences of dissemination of silicone debris are poorly understood. Currently, silicone detection in histopathological slides is based on morphological features as no specific immunohistochemical technique is available. Here, we show the feasibility and sensitivity of stimulated Raman scattering (SRS) imaging to specifically detect silicone material in stained histopathological slides, without additional sample treatment. Histology slides of four periprosthetic capsules from different implant types were obtained after explantation, as well as an enlarged axillary lymph node from a patient with a ruptured implant. SRS images coregistered with bright-field images revealed the distribution and quantity of silicone material in the tissue. Fast and high-resolution imaging of histology slides with molecular specificity using SRS provides an opportunity to investigate the role of silicone debris in the pathophysiology of implant-linked diseases.

Glycinergic signaling in the human nervous system: An overview of therapeutic drug targets and clinical effects

Glycine and related endogenous compounds (d-serine, d-alanine, sarcosine) serve critical roles in both excitatory and inhibitory neurotransmission and are influenced by a multitude of enzymes and transporters, including glycine transporter 1 and 2 (GlyT1 and GlyT2), d-amino acid oxidase (DAAO), serine racemase (SRR), alanine-serine-cysteine transporter 1 (Asc-1), and kynurenine aminotransferase (KAT). MEDLINE, Web of Science, and PsychINFO were searched for relevant human trials of compounds. Many studies utilizing exogenous administration of small molecule agonists of the glycineB site of n-methyl-d-aspartate receptor have been studied as have a growing number of glycine transporter type 1 (GlyT1) inhibitors. The clinical effects of these compounds are reviewed as are the potential effects of newer novel compounds.

Proteoglycan composition in the human sclera during growth and aging

PURPOSE

Scleral proteoglycans were characterized from human donor eyes aged 2 months to 94 years to identify age-related changes in the synthesis and/or accumulation of these extracellular matrix components.

METHODS

Newly synthesized proteoglycans (previously radiolabeled with 35SO4) and total accumulated scleral proteoglycans were extracted with 4 M guanidine hydrochloride and separated by molecular sieve chromatography on a Sepharose CL-4B column. The elution positions of newly synthesized and total accumulated proteoglycans were determined by assaying each fraction for radioactivity and glycosaminoglycans, respectively. Regression analyses were performed on the three major proteoglycan peaks to identify age-related changes in scleral proteoglycan composition. Scleral proteoglycans were further purified by anion-exchange chromatography and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analyses.

RESULTS

Human scleral proteoglycans were apparent as three major peaks after chromatography on Sepharose CL-4B. The two faster eluting peaks contained alternative forms of the cartilage proteoglycan, aggrecan, whereas the third peak contained the small proteoglycans biglycan and decorin. The relative percentage of newly synthesized and total accumulated aggrecan increased approximately two- to sixfold from infancy to 94 years. In contrast, the relative percentage of newly synthesized and total accumulated biglycan and decorin decreased by approximately 25%. Chromatography and Western blot results indicated that the absolute amounts of all three proteoglycans significantly increased in concentration within the sclera from birth to the fourth decade. Beyond the fourth decade, decorin and biglycan decreased in all scleral regions and were present in lowest concentrations by the ninth decade. In contrast, aggrecan, which was present in highest concentration in the posterior sclera, was not significantly reduced with increasing age.

CONCLUSIONS

The age-related changes in scleral proteoglycan composition observed in the present study are likely to contribute to the regional alterations in biomechanical properties of the sclera associated with growth and aging.

Primary melanoma of the vagina: a clinicopathologic analysis

Primary melanoma of the vagina is a rare tumor associated with a poor prognosis. The clinical and pathologic features of 15 patients treated at the University of Michigan Medical Center and Bowman Gray School of Medicine are reviewed. The presenting symptom of bleeding was noted in 80% of the patients. The cumulative 5-year survival was 17.4%. Two patients survived more than 5 years. All melanoma tumors were of the nodular type, 66% were located in the lower one-third of the vagina, and all patients were found to have invasion greater than 3 mm at the time of diagnosis. The majority of recurrences were located in the pelvis, with the lung being the most common metastatic site. Data from the literature were incorporated with these patients' data in a meta-analysis. Tumor thickness (6 mm or less) significantly (P = .015) affected the disease-free interval. Tumor size (less than 3 cm) significantly (P = .024) influenced survival, whereas age, stage, tumor location, and tumor thickness did not. There was no significant difference in survival among patients treated by surgical resection, irradiation, or surgical resection plus irradiation. The type of surgery, whether radical or conservative, also did not influence survival. One patient had a complete response to high-dose irradiation fractions (greater than 400 cGy), and this form of irradiation in conjunction with surgical resection is presented as a treatment option.

The role of pelvic exenteration for sarcomatous malignancies

Pelvic exenteration, although performed most frequently for recurrent squamous cell carcinoma of the cervix and vagina, has been used in selected patients with pelvic sarcoma. Nine patients with various histologic types of sarcoma treated by pelvic exenteration are reported. During this 23-year time period, 46 patients with sarcoma were evaluated for possible exenteration. Patients with embryonal rhadomyosarcoma (sarcoma botryoides) were excluded because these pediatric tumors are now treated with less radical operative procedures, plus radiation and chemotherapy. Six patients had exenteration as primary treatment, and three patients had exenteration as secondary treatment. Four patients developed recurrent disease (mean 5.2 months), and all four died of disease. Five patients were alive at 5 and 10 years, for an absolute survival of 55%. All three patients with mixed mesodermal tumors died of recurrent disease, compared with 83% survival for patients with other sarcoma types. Pelvic exenteration may play a limited but important role in the therapy of pelvic sarcoma.

The prognosis and treatment of stage I adenocarcinoma of the cervix

A review of 125 patients with stage I adenocarcinoma of the cervix is reported. The subtypes included endocervical (60), adenosquamous (38), papillary (15), clear cell (nine), and mucoid (three). The cumulative 5-year survival was 60%, and was significantly related to the following: tumor differentiation--well-differentiated 80%, moderately differentiated 69%, poorly differentiated 41%; lymph node status--nodes positive 28%, nodes negative 82%; the amount of residual disease present in the cervix after radical hysterectomy; and the interval from the previous pelvic examination. Survival was not significantly influenced by histologic subtype, patient age, number of positive lymph nodes, or tumor size beyond 3 cm. Treatment included radical hysterectomy with or without bilateral salpingo-oophorectomy, radiation therapy, radiation therapy with hysterectomy, and hysterectomy followed by radiation therapy. The best cumulative 5-year survival (93%) was found in patients treated by radical hysterectomy without bilateral salpingo-oophorectomy, whereas the poorest survival (18%) was in those treated by standard hysterectomy followed by radiation therapy. Ovarian conservation seems to be an acceptable alternative to bilateral salpingo-oophorectomy in the young patient undergoing radical hysterectomy.

Malignant schwannoma of the vulva. A case report

A woman was treated for a primary malignant schwannoma of the vulva. The initial treatment of this unusual tumor should entail radical excision of the primary. Regional lymphadenectomy probably is not helpful since metastases are generally hematogenous rather than lymphatic. Radiotherapy is ineffective as primary therapy.

Gland cell carcinoma (adenocarcinoma) of the cervix

A review of 203 patients with adenocarcinoma of the cervix treated at the University of Michigan Medical Center from 1970-1985 is reported. The following subtypes were identified: endocervical, 94 (46%); adenosquamous, 67 (33%); papillary, 21 (11%); clear cell, 16 (8%); and mucoid, five (4%). The distribution by stage of disease included stage I, 125 (62%); stage II, 40 (20%); stage III, 25 (12%); and stage IV, 13 (6%). One patient was lost to follow-up. Overall, 107 patients (53%) died from disease. The cumulative 5-year survival rate varied significantly according to the following: stage of disease--stage I 60%, stage II 47%, stage III 8%, stage IV 0%; tumor grade--well-differentiated 75%, moderately differentiated 57%, poorly differentiated 29%; lymph node status--negative nodes 79%, positive nodes 12%; patient age--less than 40 years 65%, 40-60 years 46%, over 60 years 30%; and interval from previous pelvic examination--within 1 year 65%, 1-3 years 41%, beyond 3 years 36%. The histologic subtype did not significantly influence survival. Treatment strategies should be directed at high-risk groups as defined by the stage of disease, tumor differentiation, and lymph node status.

Cervical adenocarcinoma in situ

Cervical adenocarcinoma in situ is a rare disease. Eighteen patients with this disease seen at the University of Michigan Medical Center are reported, with a review of their clinical characteristics and pathologic data. These patients represented 9.2% of all endocervical adenocarcinomas seen during the study period. Their median age was 37 years, compared with a median age of 47 years in those women with invasive disease. Sixty percent presented with abnormal bleeding. Cone biopsy margins were examined in 12 patients, and accurately predicted the presence or absence of disease in ten of 12 hysterectomy specimens. One patient developed recurrent adenocarcinoma, and died of disease 16 years after initial diagnosis. Based on these data, it is suggested that hysterectomy and pelvic lymph node evaluation be used to treat these patients.

Home dialysis and dialysis treatment modalities in the VA system

A questionnaire was sent to 50 Veterans Administration dialysis centers to inquire about treatment utilization in preparation for a Cooperative Dialysis Study. Thirty-five completed questionnaires in this survey identified a dialysis population of 2,483 patients including 452 contract patients (13.5%). The number of patients treated in-center was 1,101 (48.5%), including 239 on self-care (10.2%), and 930 patients (38.0%) were dialyzed at home. This high utilization rate of home dialysis appears in excess of three times the prevalence of home dialysis experienced overall in non-VA programs. Identification of factors responsible for the present emphasis on home programs in the VA and a corresponding analysis of non-VA programs should provide important information for the planning of future national ESRD policies.

The dilemmas of patient treatment for end-stage renal disease

In past years, physicians responsible for the treatment of chronic uremia have faced dilemmas that have been methodologic and economic while attempting to provide good patient care. These have been overcome, but in the course of time a larger one has developed. The current dilemma is one of high costs for end-stage renal disease (ESRD) management and the failure of current treatment programs to adequately rehabilitate the ESRD patient. In spite of widespread concern about this dilemma, few current data and even fewer projections exist about the eventual costs for their care. Existing data demonstrate several problems that are the basis of this dilemma: (1) the projections of incidence and prevalence of ESRD patients have been too low; (2) renal transplantation has failed to develop into a dominant (and least costly) form of ESRD therapy; (3) home dialysis programs have failed to offset the rapidly expanding in-center dialysis population; and (4) prevalence of and costs for chronic hemodialysis have increased far beyond expected levels. Using current data for the US population as to the incidence and overall mortality rate of ESRD patients, it is apparent that the dialysis population is only 39% of the way toward a steady state-corresponding to only the 4th year of a calculated 25-year growth curve. Although the current costs for maintenance of ESRD patients exceeds $1.3 billion, based upon such projections with the current distribution of patient treatment modalities, the overall annual cost will be in excess of $3.3 billion before a steady state is achieved. Improvement in mortality rates or increases in the incidence of patients will increase the steady state prevalence and the overall costs. Renal transplantation, unless kidney survival rate is increased so that it approximates patient survival, is unlikely to offset the rapidly increasing costs. New technology that would reduce the costs for center-based chronic hemodialysis has not been identified. Emphasis upon home dialysis modalities as a method of increasing patient rehabilitation and reducing costs appears to be a short-term necessity. Increased research and development in prevention of ESRD and in achieving better transplant kidney survival appear to be extremely important as long-term goals.

[Occlusive thrombotic lymphangiofibrosis of the penis]

The disease is characterized by a painless tender and mainly worm-like lesion which partly or totally encircles the distal penis, proximal of the sulcus coronarius. Usually, there are no local or regional inflammatory signs of the glans, preputium, or the inguinal lymph nodes. The anatomic target is a lymphatic collecting vessel. The pathologic process is morphologically based on three major features: lymphostasis, coagulation thrombus formation, and vessel wall thickening. We therefore propose the term lymphangiofibrosis thrombotica occlusiva. Men 20-40 years of age are most commonly affected. A therapeutic measure is not necessary, unless there is no spontaneous regression which one can except in 90% of the patients within 2 months. Mechanical and unknown microbiologic insults are discussed as etiological factors. Furthermore, the topographical distribution of blood and lymphatic vessels of the distal penis region is delineated. Six patients are presented with the clinical data.

Effects of experimental embolization of superior mesenteric artery branch on the intestine

A primary mesenteric branch of the superior mesenteric artery was embolized with Amicar-mixed clots in seven dogs and with gelatin sponges in five dogs. All of the dogs embolized with Amicar-mixed clots survived the experimental period and no mesenteric damage was found with postmortem studies. Three of the five dogs embolized with gelatin sponges showed a local stricture within the embolized segment of intestine. Collateral blood supply to the strictured segment of bowel in these three dogs developed via arterial arcades, mural branches of the vasa recta and omental arteries.

Selective arterial infusion of vasoconstrictors for control of traumatic splenic hemorrhage

The spleen of each of 20 mongrel dogs was traumatized by creating a wedge laceration, and selective arterial infusion was then performed with vasopressin in four dogs, pituitrin in eight, and epinephrine in eight. Infusion therapy with vasoconstrictors controlled the splenic hemorrhage in 19 of 20 dogs. The 15 dogs surviving the experimental period of four to eight weeks showed well-healed scars at the sites of lacerations. Three dogs had small contracted spleens as a result of massive infarction. The results of this experiment indicate that splenic hemorrhage in the experimental dogs can be controlled by selective infusion of pituitrin or vasopressin, but is more effectively controlled with epinephrine.

Bicarbonate reabsorption in the dog with experimental renal disease

Renal bicarbonate reabsorption (expressed per unit of glomerular filtration rate, GFR) has been reported to be diminished in uremic man and uremic rats. Both the increases in parathyroid hormone concentrations and in natriuretic forces have been considered to play a role in this change. The increased kaliuresis per nephron observed in chronic uremia could theoretically also contribute to inhibition of bicarbonate reabsorption. Despite the common use of normal dogs in studying bicarbonate reabsorption and of uremic dogs in studying alterations of renal function in disease, few studies of bicarbonate reabsorption in uremic dogs have been performed. In the present studies we have examined bicarbonate reabsorption in normal dogs and in dogs with experimental renal disease using a conventional bicarbonate titration technique. In unanesthetized normal dogs, the threshold for bicarbonaturia was 24.8 mEq/liter of GFR. A maximal reabsorptive rate (Tm/GFR) of 34.0 mEq/liter of GFR was obtained. In a second group of dogs, GFR was decreased to one-fifth normal. FENa was increased 16.9-fold over normal values: UKV/100 GFR and FEP were increased 5.8-fold and 10.9-fold, respectively. The threshold for bicarbonaturia in these dogs was increased to 30.5 mEq/liter of GFR and the maximal reabsorptive rate was increased to 41.2 mEq/liter of GFR. Thus, the capacity to reabsorb bicarbonate was increased despite the presence of high fractional excretion rates for sodium, potassium and phosphate. This increased reabsorptive capacity could not be accounted for by the effects of other known determinants of bicarbonate reabsorption.

Alterations in gastric physiology caused by selective embolization and vasopressin infusion of the left gastric artery

Alterations in gastric physiology caused by selective embolization and vasopressin infusion of the left gastric artery were evaluated in 29 dogs. Gastric acidity was not significantly altered following Gelfoam embolization but decreased sharply with vasopressin infusion. These results suggest that the segmental occlusion caused by Gelfoam embolization permits significant collateral blood flow to the gastric mucosa, while the arteriolar and capillary constriction caused by vasopressin effectively decreases mucosal blood flow. These findings are consistent with the clincal observation that embolization is more effective in controlling bleeding ulcers, while vasopressin infusion is more effective for controlling hemorrhagic gastritis.

An inhibitor of sodium transport in the urine of dogs with normal renal function

The urine and serum of chronically uremic patients and dogs contain an inhibitor of sodium transport that reduces short-circuit current (SCC) in the toad bladder and produces natriuresis in the rat. The present studies represent an effort to determine whether the same inhibitor is detectable in urine of normal dogs maintained on a dosium intake varying from 3 to 258 meq/day. Observations were made with and without fludrocortisone. The same Sephadex G-25 gel filtration fraction previously shown to contain the "uremic" inhibitor was tested in both the isolated toad bladder and rat bioassay systems. The fraction from dogs maintained on 258 meq qodium plus 0.2 mg fludrocortisone/day consistently inhibited SCC in the toad bladder and induced a natriuresis in the rat (P less than 0.001). The fraction from dogs on the same sodium intake without fludrocortisone was also natriuretic (P less than 0.01) but did not inhibit SCC significantly. In contrast, the fraction from dogs fed 3 meq sodium with fludrocortisone or 91 meq sodium without fludrocortisone had no significant effect in either assay system. Thus, an inhibitor of sodium transport has been found in the urine of nonuremic dogs. Both the degree of natriuresis in the rat and the degree of inhibition of SCC in the toad bladder correlated with the state of sodium balance which ensued in the dog.

Control of experimental traumatic renal hemorrhage by embolization with autogenous blood clot

Hemorrhage from artificially produced renal lacerations was controlled by selective arterial embolization with either plain or Amicar-mixed autogenous blood clot in ten dogs. The laceration sites healed as renal scars. Despite the presence of scattered, small renal infarcts caused by the embolization, hypertension did not develop in any dog during the two-month follow-up. No long-term differences could be detected between kidneys embolized with plain or modified clot. Although it is recognized that dogs have a more active fibrinolytic system than humans, the results of this study suggest that selective arterial embolization is a feasible method for controlling renal hemorrhage.

On the adaptation in sodium excretion in chronic uremia. The effects of "proportional reduction" of sodium intake

Renal mass and glomerular filtration rate (GFR) were reduced from normal to approximately 15% of normal in two groups of dogs. One group received a constant salt intake (CSI) throughout the study. The second group was subjected to "proportional reduction" of sodium intake (PRS), a dietary regimen which involved the reduction of sodium intake in exact proportion to the decrement in GFR. In the CSI group, absolute sodium excretion rate (U(Na)V) remained essentially unchanged as GFR fell, while fractional sodium excretion (FE(Na)) increased progressively from a mean control value of 0.3% to a final value of 4.4%. In the PRS group, U(Na)V decreased with each reduction in GFR and salt intake, and FE(Na) remained constant throughout. In a second study, the fraction of serum that previously has been shown to possess natriuretic activity in studies of uremic patients was obtained from a group of uremic dogs on the CSI and from another group on the PRS regimen, and the effects of the fraction was measured on sodium excretion in rats. The serum fractions from the dogs on the CSI regimen produced a significant increase in both U(Na)V and FE(Na) in the assay rats. The same serum fraction from the dogs on the PRS regimen failed to produce a significant increase in either U(Na)V or FE(Na). The data are consistent with the view that (a) The increase in FE(Na) in chronically uremic dogs is dictated by the requirements for external sodium balance and may be prevented by prospective manipulation of salt intake: (b) a natriuretic factor, previously shown to exist in the serum of patients with chronic uremia, is also demonstrable in the serum of uremic dogs; and (c) with the present bioassay system, the factor is not detectable in the serum fraction of uremic dogs in which the requirements for an increased natriuresis per nephron have been obviated.